Minor fixes to UFS error handling
v5 cover Minor fixes to UFS error handling
This series mainly fixes below two things which come along with UFS error
handling in some corner cases.
[1] Concurrency problems btw err_handler and paths like system suspend/resume/shutdown and async scan.
[2] Race condition btw UFS error recovery and task abort which happens to W-LU during suspend/resume/shutdown.
The 1st change is tested with error/fault injections to power mode change operations during system PM operations and async scan. The 2nd change is tested by mimicing SSU cmd timeout during suspend/resume/shutdown. The 3rd one is just a minor change to a check condition in IRQ handler such that the driver can dump host regs when AH8 error happens.
Change since v4:
- Fixed a typo found by Stanley.
Change since v3:
- Slightly updated some commit msg lines, no code changes.
Change since v2:
- Added one more minor change into this series.
Change since v1:
- Removed Change-Id from commit msg
Can Guo (3):
scsi: ufs: Serialize eh_work with system PM events and async scan
scsi: ufs: Fix a race condition between ufshcd_abort and eh_work
scsi: ufs: Print host regs in IRQ handler when AH8 error happens
drivers/scsi/ufs/ufshcd.c | 122 ++++++++++++++++++++++++++++++++-------------- drivers/scsi/ufs/ufshcd.h | 3 ++ 2 files changed, 88 insertions(+), 37 deletions(-)
Signature · 1 line
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
PATCH v5 1/3 scsi: ufs: Serialize eh_work with system PM events and async scan
Serialize eh_work with system PM events and async scan to make sure eh_work does not run in parallel with them.
--- drivers/scsi/ufs/ufshcd.c | 64 +++++++++++++++++++++++++++++------------------ drivers/scsi/ufs/ufshcd.h | 1 + 2 files changed, 41 insertions(+), 24 deletions(-)
drivers/scsi/ufs/ufshcd.c +40 -24
@@ -5597,7 +5597,9 @@ static inline void ufshcd_schedule_eh_work(struct ufs_hba *hba)static void ufshcd_err_handling_prepare (struct ufs_hba *hba) {pm_runtime_get_sync (hba->dev); -if (pm_runtime_suspended (hba->dev)) { +if (pm_runtime_status_suspended (hba->dev) || hba->is_sys_suspended) { +enum ufs_pm_op pm_op; +/* * Don't assume anything of pm_runtime_get_sync(), if * resume fails, irq and clocks can be OFF, and powers
@@ -5612,7 +5614,8 @@ static void ufshcd_err_handling_prepare(struct ufs_hba *hba)if (!ufshcd_is_clkgating_allowed (hba))ufshcd_setup_clocks (hba, true);ufshcd_release (hba); -ufshcd_vops_resume (hba,UFS_RUNTIME_PM ); + pm_op = hba->is_sys_suspended ?UFS_SYSTEM_PM :UFS_RUNTIME_PM ; +ufshcd_vops_resume (hba, pm_op); }else {ufshcd_hold (hba, false);if (hba->clk_scaling.is_allowed) {
@@ -5633,7 +5636,7 @@ static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)static inline bool ufshcd_err_handling_should_stop (struct ufs_hba *hba) { -return (hba->ufshcd_state ==UFSHCD_STATE_ERROR || +return (!hba->is_powered || hba->ufshcd_state ==UFSHCD_STATE_ERROR || (!(hba->saved_err || hba->saved_uic_err || hba->force_reset ||ufshcd_is_link_broken (hba)))); }
@@ -5646,6 +5649,7 @@ static void ufshcd_recover_pm_error(struct ufs_hba *hba)struct request_queue *q;int ret; + hba->is_sys_suspended = false;/* * Set RPM status of hba device to RPM_ACTIVE, * this also clears its runtime error.
@@ -5704,11 +5708,13 @@ static void ufshcd_err_handler(struct work_struct *work) hba = container_of(work, struct ufs_hba, eh_work); +down (&hba->eh_sem);spin_lock_irqsave (hba->host->host_lock, flags);if (ufshcd_err_handling_should_stop (hba)) {if (hba->ufshcd_state !=UFSHCD_STATE_ERROR ) hba->ufshcd_state =UFSHCD_STATE_OPERATIONAL ;spin_unlock_irqrestore (hba->host->host_lock, flags); +up (&hba->eh_sem);return ; }ufshcd_set_eh_in_progress (hba);
@@ -5716,20 +5722,18 @@ static void ufshcd_err_handler(struct work_struct *work)ufshcd_err_handling_prepare (hba);spin_lock_irqsave (hba->host->host_lock, flags);ufshcd_scsi_block_requests (hba); -/* -* A full reset and restore might have happened after preparation -* is finished, double check whether we should stop. -*/ -if (ufshcd_err_handling_should_stop (hba)) { -if (hba->ufshcd_state !=UFSHCD_STATE_ERROR ) - hba->ufshcd_state =UFSHCD_STATE_OPERATIONAL ; - goto out; - } hba->ufshcd_state =UFSHCD_STATE_RESET ;/* Complete requests that have door-bell cleared by h/w */ ufshcd_complete_requests (hba); +/* +* A full reset and restore might have happened after preparation +* is finished, double check whether we should stop. +*/ +if (ufshcd_err_handling_should_stop (hba)) + goto skip_err_handling; +if (hba->dev_quirks &UFS_DEVICE_QUIRK_RECOVERY_FROM_DL_NAC_ERRORS ) {bool ret;
@@ -5737,17 +5741,10 @@ static void ufshcd_err_handler(struct work_struct *work)/* release the lock as ufshcd_quirk_dl_nac_errors() may sleep */ ret =ufshcd_quirk_dl_nac_errors (hba);spin_lock_irqsave (hba->host->host_lock, flags); -if (!ret && !hba->force_reset &&ufshcd_is_link_active (hba)) +if (!ret &&ufshcd_err_handling_should_stop (hba)) goto skip_err_handling; } -if (hba->force_reset ||ufshcd_is_link_broken (hba) || -ufshcd_is_saved_err_fatal (hba) || - ((hba->saved_err &UIC_ERROR ) && - (hba->saved_uic_err & (UFSHCD_UIC_DL_NAC_RECEIVED_ERROR | - UFSHCD_UIC_DL_TCx_REPLAY_ERROR)))) - needs_reset = true; -if ((hba->saved_err & (INT_FATAL_ERRORS |UFSHCD_UIC_HIBERN8_MASK )) || (hba->saved_uic_err && (hba->saved_uic_err !=UFSHCD_UIC_PA_GENERIC_ERROR ))) {
@@ -5767,8 +5764,14 @@ static void ufshcd_err_handler(struct work_struct *work)* transfers forcefully because they will get cleared during * host reset and restore */ -if (needs_reset) +if (hba->force_reset ||ufshcd_is_link_broken (hba) || +ufshcd_is_saved_err_fatal (hba) || + ((hba->saved_err &UIC_ERROR ) && + (hba->saved_uic_err & (UFSHCD_UIC_DL_NAC_RECEIVED_ERROR | + UFSHCD_UIC_DL_TCx_REPLAY_ERROR)))) { + needs_reset = true; goto do_reset; + }/* * If LINERESET was caught, UFS might have been put to PWM mode,
@@ -5876,12 +5879,11 @@ static void ufshcd_err_handler(struct work_struct *work)dev_err_ratelimited (hba->dev,"%s: exit: saved_err 0x%x saved_uic_err 0x%x" , __func__, hba->saved_err, hba->saved_uic_err); } - -out:ufshcd_clear_eh_in_progress (hba);spin_unlock_irqrestore (hba->host->host_lock, flags);ufshcd_scsi_unblock_requests (hba);ufshcd_err_handling_unprepare (hba); +up (&hba->eh_sem); }/**
@@ -6856,6 +6858,7 @@ static int ufshcd_reset_and_restore(struct ufs_hba *hba)*/ scsi_report_bus_reset (hba->host,0 );if (err) { + hba->ufshcd_state =UFSHCD_STATE_ERROR ; hba->saved_err |= saved_err; hba->saved_uic_err |= saved_uic_err; }
@@ -7704,8 +7707,10 @@ static void ufshcd_async_scan(void *data, async_cookie_t cookie)struct ufs_hba *hba = (struct ufs_hba *)data;int ret; +down (&hba->eh_sem);/* Initialize hba, detect and initialize UFS device */ ret =ufshcd_probe_hba (hba, true); +up (&hba->eh_sem);if (ret) goto out;
@@ -8718,6 +8723,7 @@ int ufshcd_system_suspend(struct ufs_hba *hba)int ret =0 ;ktime_t start =ktime_get (); +down (&hba->eh_sem);if (!hba || !hba->is_powered)return 0 ;
@@ -8748,6 +8754,8 @@ int ufshcd_system_suspend(struct ufs_hba *hba) hba->curr_dev_pwr_mode, hba->uic_link_state);if (!ret) hba->is_sys_suspended = true; +else +up (&hba->eh_sem);return ret; }EXPORT_SYMBOL (ufshcd_system_suspend);
@@ -8764,8 +8772,10 @@ int ufshcd_system_resume(struct ufs_hba *hba)int ret =0 ;ktime_t start =ktime_get (); -if (!hba) +if (!hba) { +up (&hba->eh_sem);return -EINVAL ; + }if (!hba->is_powered ||pm_runtime_suspended (hba->dev))/*
@@ -8781,6 +8791,7 @@ int ufshcd_system_resume(struct ufs_hba *hba) hba->curr_dev_pwr_mode, hba->uic_link_state);if (!ret) hba->is_sys_suspended = false; +up (&hba->eh_sem);return ret; }EXPORT_SYMBOL (ufshcd_system_resume);
@@ -8872,6 +8883,7 @@ int ufshcd_shutdown(struct ufs_hba *hba) {int ret =0 ; +down (&hba->eh_sem);if (!hba->is_powered) goto out;
@@ -8888,6 +8900,8 @@ int ufshcd_shutdown(struct ufs_hba *hba) out:if (ret)dev_err (hba->dev,"%s failed, err %d\n" , __func__, ret); + hba->is_powered = false; +up (&hba->eh_sem);/* allow force shutdown even in case of errors */ return 0 ; }
@@ -9082,6 +9096,8 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)INIT_WORK (&hba->eh_work, ufshcd_err_handler);INIT_WORK (&hba->eeh_work, ufshcd_exception_event_handler); +sema_init (&hba->eh_sem,1 ); +/* Initialize UIC command mutex */ mutex_init (&hba->uic_cmd_mutex);
drivers/scsi/ufs/ufshcd.h +1 -0
@@ -728,6 +728,7 @@ struct ufs_hba {u32 intr_mask;u16 ee_ctrl_mask;bool is_powered; +struct semaphore eh_sem;/* Work Queues */ struct workqueue_struct *eh_wq;
Signature · 1 line
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
Re: [PATCH V5 1/3] scsi: ufs: Serialize eh_work with system PM events and async scan
Quoted 6 lines · Can Guo
Serialize
eh_workwith system PM events and async scan to make sureeh_workdoes not run in parallel with them.Reviewed-by Asutosh Das <[email protected]>Reviewed-by Hongwu Su<[email protected]>Signed-off-by Can Guo <[email protected]>
Re: [PATCH V5 1/3] scsi: ufs: Serialize eh_work with system PM events and async scan
In reply to Can GuoQuoted 248 lines · Can Guo
Serialize
eh_workwith system PM events and async scan to make sureeh_workdoes not run in parallel with them.Reviewed-by Asutosh Das <[email protected]>Reviewed-by Hongwu Su<[email protected]>Signed-off-by Can Guo <[email protected]>--- drivers/scsi/ufs/ufshcd.c | 64 +++++++++++++++++++++++++++++------------------ drivers/scsi/ufs/ufshcd.h | 1 + 2 files changed, 41 insertions(+), 24 deletions(-)drivers/scsi/ufs/ufshcd.c +3
-1@@ -5597,7 +5597,9 @@ static inline void ufshcd_schedule_eh_work(struct ufs_hba *hba) static void ufshcd_err_handling_prepare(struct ufs_hba *hba) {pm_runtime_get_sync (hba->dev); -if (pm_runtime_suspended (hba->dev)) { +if (pm_runtime_status_suspended (hba->dev) || hba->is_sys_suspended) { +enum ufs_pm_op pm_op; +/* * Don't assume anything of pm_runtime_get_sync(), if drivers/scsi/ufs/ufshcd.c +2
-1* resume fails, irq and clocks can be OFF, and powers @@ -5612,7 +5614,8 @@ static void ufshcd_err_handling_prepare(struct ufs_hba *hba)if (!ufshcd_is_clkgating_allowed (hba))ufshcd_setup_clocks (hba, true);ufshcd_release (hba); -ufshcd_vops_resume (hba,UFS_RUNTIME_PM ); + pm_op = hba->is_sys_suspended ?UFS_SYSTEM_PM :UFS_RUNTIME_PM ; +ufshcd_vops_resume (hba, pm_op); }else {ufshcd_hold (hba, false);drivers/scsi/ufs/ufshcd.c +1
-1if (hba->clk_scaling.is_allowed) {@@ -5633,7 +5636,7 @@ static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)static inline bool ufshcd_err_handling_should_stop (struct ufs_hba *hba) { - return (hba->ufshcd_state == UFSHCD_STATE_ERROR || + return (!hba->is_powered || hba->ufshcd_state == UFSHCD_STATE_ERROR||
drivers/scsi/ufs/ufshcd.c +1
-0(!(hba->saved_err || hba->saved_uic_err || hba->force_reset || ufshcd_is_link_broken(hba)))); }@@ -5646,6 +5649,7 @@ static void ufshcd_recover_pm_error(struct ufs_hba *hba)struct request_queue *q;int ret; + hba->is_sys_suspended = false;/* * Set RPM status of hba device to RPM_ACTIVE, drivers/scsi/ufs/ufshcd.c +2
-0* this also clears its runtime error. @@ -5704,11 +5708,13 @@ static void ufshcd_err_handler(struct work_struct *work) hba = container_of(work, struct ufs_hba, eh_work); +down (&hba->eh_sem);spin_lock_irqsave (hba->host->host_lock, flags);if (ufshcd_err_handling_should_stop (hba)) {if (hba->ufshcd_state !=UFSHCD_STATE_ERROR ) hba->ufshcd_state =UFSHCD_STATE_OPERATIONAL ;spin_unlock_irqrestore (hba->host->host_lock, flags); +up (&hba->eh_sem);return ; }drivers/scsi/ufs/ufshcd.c +8
-17ufshcd_set_eh_in_progress (hba);@@ -5716,20 +5722,18 @@ static void ufshcd_err_handler(struct work_struct *work)ufshcd_err_handling_prepare (hba );spin_lock_irqsave (hba->host->host_lock, flags);ufshcd_scsi_block_requests (hba); -/* -* A full reset and restore might have happened after preparation -* is finished, double check whether we should stop. -*/ -if (ufshcd_err_handling_should_stop (hba)) { -if (hba->ufshcd_state !=UFSHCD_STATE_ERROR ) - hba->ufshcd_state =UFSHCD_STATE_OPERATIONAL ; - goto out; - } hba->ufshcd_state =UFSHCD_STATE_RESET ;/* Complete requests that have door-bell cleared by h/w */ ufshcd_complete_requests (hba); +/* +* A full reset and restore might have happened after preparation +* is finished, double check whether we should stop. +*/ +if (ufshcd_err_handling_should_stop (hba)) + goto skip_err_handling; +if (hba->dev_quirks &UFS_DEVICE_QUIRK_RECOVERY_FROM_DL_NAC_ERRORS ) {bool ret;@@ -5737,17 +5741,10 @@ static void ufshcd_err_handler(struct work_struct *work)/* release the lock as ufshcd_quirk_dl_nac_errors() may sleep */ ret =ufshcd_quirk_dl_nac_errors (hba);spin_lock_irqsave (hba->host->host_lock, flags); -if (!ret && !hba->force_reset &&ufshcd_is_link_active (hba)) +if (!ret &&ufshcd_err_handling_should_stop (hba)) goto skip_err_handling; } -if (hba->force_reset ||ufshcd_is_link_broken (hba) || -ufshcd_is_saved_err_fatal (hba) || - ((hba->saved_err &UIC_ERROR ) && - (hba->saved_uic_err & (UFSHCD_UIC_DL_NAC_RECEIVED_ERROR | - UFSHCD_UIC_DL_TCx_REPLAY_ERROR)))) - needs_reset = true; - if ((hba->saved_err & (INT_FATAL_ERRORS | UFSHCD_UIC_HIBERN8_MASK))||
drivers/scsi/ufs/ufshcd.c +7
-1(hba->saved_uic_err && (hba->saved_uic_err != UFSHCD_UIC_PA_GENERIC_ERROR))) {@@ -5767,8 +5764,14 @@ static void ufshcd_err_handler(structwork_struct *work) * transfers forcefully because they will get cleared during * host reset and restore */ -if (needs_reset) +if (hba->force_reset ||ufshcd_is_link_broken (hba) || +ufshcd_is_saved_err_fatal (hba) || + ((hba->saved_err &UIC_ERROR ) && + (hba->saved_uic_err & (UFSHCD_UIC_DL_NAC_RECEIVED_ERROR | + UFSHCD_UIC_DL_TCx_REPLAY_ERROR)))) { + needs_reset = true; goto do_reset; + }/* drivers/scsi/ufs/ufshcd.c +1
-2* If LINERESET was caught, UFS might have been put to PWM mode, @@ -5876,12 +5879,11 @@ static void ufshcd_err_handler(struct work_struct *work) dev_err_ratelimited(hba->dev, "%s: exit: saved_err 0x%x saved_uic_err 0x%x", __func__, hba->saved_err, hba->saved_uic_err); } - -out:ufshcd_clear_eh_in_progress (hba);spin_unlock_irqrestore (hba->host->host_lock, flags);ufshcd_scsi_unblock_requests (hba);ufshcd_err_handling_unprepare (hba); +up (&hba->eh_sem); }/**
drivers/scsi/ufs/ufshcd.c +1
-0@@ -6856,6 +6858,7 @@ static int ufshcd_reset_and_restore(structufs_hba *hba) */ scsi_report_bus_reset (hba->host,0 );if (err) { + hba->ufshcd_state =UFSHCD_STATE_ERROR ; hba->saved_err |= saved_err; hba->saved_uic_err |= saved_uic_err;drivers/scsi/ufs/ufshcd.c +14
-1}@@ -7704,8 +7707,10 @@ static void ufshcd_async_scan(void *data, async_cookie_t cookie)struct ufs_hba *hba = (struct ufs_hba *)data;int ret; +down (&hba->eh_sem);/* Initialize hba, detect and initialize UFS device */ ret =ufshcd_probe_hba (hba, true); +up (&hba->eh_sem);if (ret) goto out;@@ -8718,6 +8723,7 @@ int ufshcd_system_suspend(struct ufs_hba *hba)int ret =0 ;ktime_t start =ktime_get (); +down (&hba->eh_sem);if (!hba || !hba->is_powered)return 0 ;@@ -8748,6 +8754,8 @@ int ufshcd_system_suspend(struct ufs_hba *hba) hba->curr_dev_pwr_mode, hba->uic_link_state);if (!ret) hba->is_sys_suspended = true; +else +up (&hba->eh_sem);return ret; }EXPORT_SYMBOL (ufshcd_system_suspend);@@ -8764,8 +8772,10 @@ int ufshcd_system_resume(struct ufs_hba *hba)int ret =0 ;ktime_t start =ktime_get (); -if (!hba) +if (!hba) { +up (&hba->eh_sem);return -EINVAL ; + }if (!hba->is_powered ||pm_runtime_suspended (hba->dev))/* @@ -8781,6 +8791,7 @@ int ufshcd_system_resume(struct ufs_hba *hba) hba->curr_dev_pwr_mode, hba->uic_link_state);if (!ret) hba->is_sys_suspended = false; +up (&hba->eh_sem);return ret; }EXPORT_SYMBOL (ufshcd_system_resume);@@ -8872,6 +8883,7 @@ int ufshcd_shutdown(struct ufs_hba *hba) {int ret =0 ; +down (&hba->eh_sem);if (!hba->is_powered) goto out;@@ -8888,6 +8900,8 @@ int ufshcd_shutdown(struct ufs_hba *hba) out:if (ret)dev_err (hba->dev,"%s failed, err %d\n" , __func__, ret); + hba->is_powered = false; +up (&hba->eh_sem);/* allow force shutdown even in case of errors */ return 0 ; }@@ -9082,6 +9096,8 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) INIT_WORK(&hba->eh_work, ufshcd_err_handler);INIT_WORK (&hba->eeh_work, ufshcd_exception_event_handler); +sema_init (&hba->eh_sem,1 ); +/* Initialize UIC command mutex */ mutex_init (&hba->uic_cmd_mutex);drivers/scsi/ufs/ufshcd.h +0
-0
drivers/scsi/ufs/ufshcd.h struct ufs_hba { · line 734
Quoted 7 lines
drivers/scsi/ufs/ufshcd.h +1
-0@@ -728,6 +728,7 @@ struct ufs_hba {u32 intr_mask;u16 ee_ctrl_mask;bool is_powered; +struct semaphore eh_sem;/* Work Queues */ struct workqueue_struct *eh_wq;
PATCH v5 2/3 scsi: ufs: Fix a race condition between ufshcd_abort and eh_work
In reply to Can GuoIn current task abort routine, if task abort happens to the device W-LU, the code directly jumps to ufshcd_eh_host_reset_handler() to perform a full reset and restore then returns FAIL or SUCCESS. Commands sent to the device W-LU are most likely the SSU cmds sent during UFS PM operations. If such SSU cmd enters task abort routine, when ufshcd_eh_host_reset_handler() flushes eh_work, it will get stuck there since err_handler is serialized with PM operations.
In order to unblock above call path, we merely clean up the lrb taken by this cmd, queue the eh_work and return SUCCESS. Once the cmd is aborted, the PM operation which sends out the cmd just errors out, then err_handler shall be able to proceed with the full reset and restore.
In this scenario, the cmd is aborted even before it is actually cleared by HW, set the lrb->in_use flag to prevent subsequent cmds, including SCSI cmds and dev cmds, from taking the lrb released from abort. The flag shall evetually be cleared in __ufshcd_transfer_req_compl() invoked by the full reset and restore from err_handler.
--- drivers/scsi/ufs/ufshcd.c | 55 ++++++++++++++++++++++++++++++++++++----------- drivers/scsi/ufs/ufshcd.h | 2 ++ 2 files changed, 45 insertions(+), 12 deletions(-)
drivers/scsi/ufs/ufshcd.c +43 -12
@@ -2539,6 +2539,14 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) (hba->clk_gating.state != CLKS_ON)); lrbp = &hba->lrb[tag]; +if (unlikely (lrbp->in_use)) { +if (hba->pm_op_in_progress) +set_host_byte (cmd,DID_BAD_TARGET ); +else + err =SCSI_MLQUEUE_HOST_BUSY ; +ufshcd_release (hba); + goto out; + }WARN_ON (lrbp->cmd); lrbp->cmd = cmd;
@@ -2781,6 +2789,11 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba,init_completion (&wait); lrbp = &hba->lrb[tag]; +if (unlikely (lrbp->in_use)) { + err = -EBUSY ; + goto out; + } +WARN_ON (lrbp->cmd); err =ufshcd_compose_dev_cmd (hba, lrbp, cmd_type, tag);if (unlikely (err))
@@ -2797,6 +2810,7 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, err =ufshcd_wait_for_dev_cmd (hba, lrbp, timeout); +out:ufshcd_add_query_upiu_trace (hba, tag, err ?"query_complete_err" :"query_complete" );
@@ -4932,6 +4946,7 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,for_each_set_bit (index, &completed_reqs, hba->nutrs) { lrbp = &hba->lrb[index]; + lrbp->in_use = false; lrbp->compl_time_stamp =ktime_get (); cmd = lrbp->cmd;if (cmd) {
@@ -6374,8 +6389,12 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba,init_completion (&wait); lrbp = &hba->lrb[tag]; -WARN_ON (lrbp->cmd); +if (unlikely (lrbp->in_use)) { + err = -EBUSY ; + goto out; + } +WARN_ON (lrbp->cmd); lrbp->cmd =NULL ; lrbp->sense_bufflen =0 ; lrbp->sense_buffer =NULL ;
@@ -6447,6 +6466,7 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba, } } +out:blk_put_request (req); out_unlock:up_read (&hba->clk_scaling_lock);
@@ -6696,16 +6716,6 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)BUG (); } -/* -* Task abort to the device W-LUN is illegal. When this command -* will fail, due to spec violation, scsi err handling next step -* will be to send LU reset which, again, is a spec violation. -* To avoid these unnecessary/illegal step we skip to the last error -* handling stage: reset and restore. -*/ -if (lrbp->lun ==UFS_UPIU_UFS_DEVICE_WLUN ) -return ufshcd_eh_host_reset_handler (cmd); -ufshcd_hold (hba, false); reg =ufshcd_readl (hba,REG_UTP_TRANSFER_REQ_DOOR_BELL );/* If command is already aborted/completed, return SUCCESS */
@@ -6726,7 +6736,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)* to reduce repeated printouts. For other aborted requests only print * basic details. */ -scsi_print_command (hba->lrb[tag].cmd); +scsi_print_command (cmd);if (!hba->req_abort_count) {ufshcd_update_reg_hist (&hba->ufs_stats.task_abort,0 );ufshcd_print_host_regs (hba);
@@ -6745,6 +6755,27 @@ static int ufshcd_abort(struct scsi_cmnd *cmd) goto cleanup; } +/* +* Task abort to the device W-LUN is illegal. When this command +* will fail, due to spec violation, scsi err handling next step +* will be to send LU reset which, again, is a spec violation. +* To avoid these unnecessary/illegal steps, first we clean up +* the lrb taken by this cmd and mark the lrb as in_use, then +* queue the eh_work and bail. +*/ +if (lrbp->lun ==UFS_UPIU_UFS_DEVICE_WLUN ) { +spin_lock_irqsave (host->host_lock, flags); +if (lrbp->cmd) { +__ufshcd_transfer_req_compl (hba, (1UL << tag)); +__set_bit (tag, &hba->outstanding_reqs); + lrbp->in_use = true; + hba->force_reset = true; +ufshcd_schedule_eh_work (hba); + } +spin_unlock_irqrestore (host->host_lock, flags); + goto out; + } +/* Skip task abort in case previous aborts failed and report failure */ if (lrbp->req_abort_skip) err = -EIO ;
drivers/scsi/ufs/ufshcd.h +2 -0
@@ -163,6 +163,7 @@ struct ufs_pm_lvl_states {* @crypto_key_slot: the key slot to use for inline crypto (-1 if none) * @data_unit_num: the data unit number for the first block for inline crypto * @req_abort_skip: skip request abort task flag +* @in_use: indicates that this lrb is still in use */ struct ufshcd_lrb {struct utp_transfer_req_desc *utr_descriptor_ptr;
@@ -192,6 +193,7 @@ struct ufshcd_lrb {#endif bool req_abort_skip; +bool in_use; };/**
Signature · 1 line
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
Re: [PATCH V5 2/3] scsi: ufs: Fix a race condition between ufshcd_abort and eh_work
Hi Can,
Quoted 127 lines · Can Guo
In current task abort routine, if task abort happens to the device W-LU, the code directly jumps to
ufshcd_eh_host_reset_handler()to perform a full reset and restore then returns FAIL or SUCCESS. Commands sent to the device W-LU are most likely the SSU cmds sent during UFS PM operations. If such SSU cmd enters task abort routine, whenufshcd_eh_host_reset_handler()flusheseh_work, it will get stuck there sinceerr_handleris serialized with PM operations.In order to unblock above call path, we merely clean up the lrb taken by this cmd, queue the
eh_workand return SUCCESS. Once the cmd is aborted, the PM operation which sends out the cmd just errors out, thenerr_handlershall be able to proceed with the full reset and restore.In this scenario, the cmd is aborted even before it is actually cleared by HW, set the
lrb->in_useflag to prevent subsequent cmds, including SCSI cmds and dev cmds, from taking the lrb released from abort. The flag shall evetually be cleared in__ufshcd_transfer_req_compl()invoked by the full reset and restore fromerr_handler.Reviewed-by Asutosh Das <[email protected]>Signed-off-by Can Guo <[email protected]>--- drivers/scsi/ufs/ufshcd.c | 55 ++++++++++++++++++++++++++++++++++++----------- drivers/scsi/ufs/ufshcd.h | 2 ++ 2 files changed, 45 insertions(+), 12 deletions(-)drivers/scsi/ufs/ufshcd.c +24
-12@@ -2539,6 +2539,14 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) (hba->clk_gating.state != CLKS_ON)); lrbp = &hba->lrb[tag]; +if (unlikely (lrbp->in_use)) { +if (hba->pm_op_in_progress) +set_host_byte (cmd,DID_BAD_TARGET ); +else + err =SCSI_MLQUEUE_HOST_BUSY ; +ufshcd_release (hba); + goto out; + }WARN_ON (lrbp->cmd); lrbp->cmd = cmd;@@ -2781,6 +2789,11 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba,init_completion (&wait); lrbp = &hba->lrb[tag]; +if (unlikely (lrbp->in_use)) { + err = -EBUSY ; + goto out; + } +WARN_ON (lrbp->cmd); err =ufshcd_compose_dev_cmd (hba, lrbp, cmd_type, tag);if (unlikely (err))@@ -2797,6 +2810,7 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, err =ufshcd_wait_for_dev_cmd (hba, lrbp, timeout); +out:ufshcd_add_query_upiu_trace (hba, tag, err ?"query_complete_err" :"query_complete" );@@ -4932,6 +4946,7 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,for_each_set_bit (index, &completed_reqs, hba->nutrs) { lrbp = &hba->lrb[index]; + lrbp->in_use = false; lrbp->compl_time_stamp =ktime_get (); cmd = lrbp->cmd;if (cmd) {@@ -6374,8 +6389,12 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba,init_completion (&wait); lrbp = &hba->lrb[tag]; -WARN_ON (lrbp->cmd); +if (unlikely (lrbp->in_use)) { + err = -EBUSY ; + goto out; + } +WARN_ON (lrbp->cmd); lrbp->cmd =NULL ; lrbp->sense_bufflen =0 ; lrbp->sense_buffer =NULL ;@@ -6447,6 +6466,7 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba, } } +out:blk_put_request (req); out_unlock:up_read (&hba->clk_scaling_lock);@@ -6696,16 +6716,6 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)BUG (); } -/* -* Task abort to the device W-LUN is illegal. When this command -* will fail, due to spec violation, scsi err handling next step -* will be to send LU reset which, again, is a spec violation. -* To avoid these unnecessary/illegal step we skip to the last error -* handling stage: reset and restore. -*/ -if (lrbp->lun ==UFS_UPIU_UFS_DEVICE_WLUN ) -return ufshcd_eh_host_reset_handler (cmd); -ufshcd_hold (hba, false); reg =ufshcd_readl (hba,REG_UTP_TRANSFER_REQ_DOOR_BELL );/* If command is already aborted/completed, return SUCCESS */ @@ -6726,7 +6736,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)* to reduce repeated printouts. For other aborted requests only print * basic details. */ -scsi_print_command (hba->lrb[tag].cmd); +scsi_print_command (cmd);if (!hba->req_abort_count) {ufshcd_update_reg_hist (&hba->ufs_stats.task_abort,0 );ufshcd_print_host_regs (hba);@@ -6745,6 +6755,27 @@ static int ufshcd_abort(struct scsi_cmnd *cmd) goto cleanup; } +/* +* Task abort to the device W-LUN is illegal. When this command
drivers/scsi/ufs/ufshcd.c static int ufshcd_abort(struct scsi_cmnd *cmd) · line 6769
Quoted 10 lines
drivers/scsi/ufs/ufshcd.c +10
-0+* will fail, due to spec violation, scsi err handling next step +* will be to send LU reset which, again, is a spec violation. +* To avoid these unnecessary/illegal steps, first we clean up +* the lrb taken by this cmd and mark the lrb as in_use, then +* queue the eh_work and bail. +*/ +if (lrbp->lun ==UFS_UPIU_UFS_DEVICE_WLUN ) { +spin_lock_irqsave (host->host_lock, flags); +if (lrbp->cmd) { +__ufshcd_transfer_req_compl (hba, (1UL << tag));
The timed out "tag" is cleared once here.
drivers/scsi/ufs/ufshcd.c static int ufshcd_abort(struct scsi_cmnd *cmd) · line 6773
Quoted 4 lines
drivers/scsi/ufs/ufshcd.c +4
-0+__set_bit (tag, &hba->outstanding_reqs); + lrbp->in_use = true; + hba->force_reset = true; +ufshcd_schedule_eh_work (hba);
The same "tag" would be cleared again in error handler with __ufshcd_transfer_req_compl().
In __ufshcd_transfer_req_compl, hba->clk_scaling.active_reqs will be decreased if clk-scaling is supported as below,
if (ufshcd_is_clkscaling_supported(hba)) hba->clk_scaling.active_reqs--;
Will be the hba->clk_scaling.active_reqs value become abnormal by this flow?
Thanks,
Stanley Chu
Quoted 28 lines
drivers/scsi/ufs/ufshcd.c +5
-0+ } +spin_unlock_irqrestore (host->host_lock, flags); + goto out; + } +/* Skip task abort in case previous aborts failed and report failure */ if (lrbp->req_abort_skip) err = -EIO ;drivers/scsi/ufs/ufshcd.h +2
-0@@ -163,6 +163,7 @@ struct ufs_pm_lvl_states {* @crypto_key_slot: the key slot to use for inline crypto (-1 if none) * @data_unit_num: the data unit number for the first block for inline crypto * @req_abort_skip: skip request abort task flag +* @in_use: indicates that this lrb is still in use */ struct ufshcd_lrb {struct utp_transfer_req_desc *utr_descriptor_ptr;@@ -192,6 +193,7 @@ struct ufshcd_lrb {#endif bool req_abort_skip; +bool in_use; };/**
Re: [PATCH V5 2/3] scsi: ufs: Fix a race condition between ufshcd_abort and eh_work
Quoted 159 lines · Stanley Chu
Hi Can,
Quoted 135 lines · Can Guo
In current task abort routine, if task abort happens to the device W-LU, the code directly jumps to
ufshcd_eh_host_reset_handler()to perform a full reset and restore then returns FAIL or SUCCESS. Commands sent to the device W-LU are most likely the SSU cmds sent during UFS PM operations. If such SSU cmd enters task abort routine, whenufshcd_eh_host_reset_handler()flusheseh_work, it will get stuck there sinceerr_handleris serialized with PM operations.In order to unblock above call path, we merely clean up the lrb taken by this cmd, queue the
eh_workand return SUCCESS. Once the cmd is aborted, the PM operation which sends out the cmd just errors out, thenerr_handlershall be able to proceed with the full reset and restore.In this scenario, the cmd is aborted even before it is actually cleared by HW, set the
lrb->in_useflag to prevent subsequent cmds, including SCSI cmds and dev cmds, from taking the lrb released from abort. The flag shall evetually be cleared in__ufshcd_transfer_req_compl()invoked by the full reset and restore fromerr_handler.Reviewed-by Asutosh Das <[email protected]>Signed-off-by Can Guo <[email protected]>--- drivers/scsi/ufs/ufshcd.c | 55 ++++++++++++++++++++++++++++++++++++----------- drivers/scsi/ufs/ufshcd.h | 2 ++ 2 files changed, 45 insertions(+), 12 deletions(-)drivers/scsi/ufs/ufshcd.c +8
-0@@ -2539,6 +2539,14 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) (hba->clk_gating.state != CLKS_ON)); lrbp = &hba->lrb[tag]; +if (unlikely (lrbp->in_use)) { +if (hba->pm_op_in_progress) +set_host_byte (cmd,DID_BAD_TARGET ); +else + err =SCSI_MLQUEUE_HOST_BUSY ; +ufshcd_release (hba); + goto out; + }WARN_ON (lrbp->cmd);drivers/scsi/ufs/ufshcd.c +5
-0lrbp->cmd = cmd;@@ -2781,6 +2789,11 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba,init_completion (&wait); lrbp = &hba->lrb[tag]; +if (unlikely (lrbp->in_use)) { + err = -EBUSY ; + goto out; + } +WARN_ON (lrbp->cmd); err =ufshcd_compose_dev_cmd (hba, lrbp, cmd_type, tag);drivers/scsi/ufs/ufshcd.c +2
-0if (unlikely (err))@@ -2797,6 +2810,7 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, err =ufshcd_wait_for_dev_cmd (hba, lrbp, timeout); +out:ufshcd_add_query_upiu_trace (hba, tag, err ?"query_complete_err" :"query_complete" );@@ -4932,6 +4946,7 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba, for_each_set_bit(index, &completed_reqs, hba->nutrs) { lrbp = &hba->lrb[index]; + lrbp->in_use = false; lrbp->compl_time_stamp =ktime_get (); cmd = lrbp->cmd;drivers/scsi/ufs/ufshcd.c +5
-1if (cmd) {@@ -6374,8 +6389,12 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba,init_completion (&wait); lrbp = &hba->lrb[tag]; -WARN_ON (lrbp->cmd); +if (unlikely (lrbp->in_use)) { + err = -EBUSY ; + goto out; + } +WARN_ON (lrbp->cmd); lrbp->cmd =NULL ; lrbp->sense_bufflen =0 ;drivers/scsi/ufs/ufshcd.c +1
-0lrbp->sense_buffer =NULL ;@@ -6447,6 +6466,7 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba, } } +out:blk_put_request (req); out_unlock:drivers/scsi/ufs/ufshcd.c +0
-10up_read (&hba->clk_scaling_lock);@@ -6696,16 +6716,6 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)BUG (); } -/* -* Task abort to the device W-LUN is illegal. When this command -* will fail, due to spec violation, scsi err handling next step -* will be to send LU reset which, again, is a spec violation. -* To avoid these unnecessary/illegal step we skip to the last error -* handling stage: reset and restore. -*/ -if (lrbp->lun ==UFS_UPIU_UFS_DEVICE_WLUN ) -return ufshcd_eh_host_reset_handler (cmd); -ufshcd_hold (hba, false); reg =ufshcd_readl (hba,REG_UTP_TRANSFER_REQ_DOOR_BELL );/* If command is already aborted/completed, return SUCCESS */ @@ -6726,7 +6736,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)* to reduce repeated printouts. For other aborted requests only drivers/scsi/ufs/ufshcd.c +3
-1* basic details. */ -scsi_print_command (hba->lrb[tag].cmd); +scsi_print_command (cmd);if (!hba->req_abort_count) {ufshcd_update_reg_hist (&hba->ufs_stats.task_abort,0 );ufshcd_print_host_regs (hba);@@ -6745,6 +6755,27 @@ static int ufshcd_abort(struct scsi_cmnd *cmd) goto cleanup; } +/* +* Task abort to the device W-LUN is illegal. When this command drivers/scsi/ufs/ufshcd.c static int ufshcd_abort(struct scsi_cmnd *cmd) · line 6769
Quoted 10 lines
drivers/scsi/ufs/ufshcd.c +10
-0+* will fail, due to spec violation, scsi err handling next step +* will be to send LU reset which, again, is a spec violation. +* To avoid these unnecessary/illegal steps, first we clean up +* the lrb taken by this cmd and mark the lrb as in_use, then +* queue the eh_work and bail. +*/ +if (lrbp->lun ==UFS_UPIU_UFS_DEVICE_WLUN ) { +spin_lock_irqsave (host->host_lock, flags); +if (lrbp->cmd) { +__ufshcd_transfer_req_compl (hba, (1UL << tag));The timed out "tag" is cleared once here.
drivers/scsi/ufs/ufshcd.c static int ufshcd_abort(struct scsi_cmnd *cmd) · line 6773
Quoted 4 lines
drivers/scsi/ufs/ufshcd.c +4
-0+__set_bit (tag, &hba->outstanding_reqs); + lrbp->in_use = true; + hba->force_reset = true; +ufshcd_schedule_eh_work (hba);The same "tag" would be cleared again in error handler with
__ufshcd_transfer_req_compl().
Quoted 9 lines
In
__ufshcd_transfer_req_compl,hba->clk_scaling.active_reqswill be decreased if clk-scaling is supported as below,if (ufshcd_is_clkscaling_supported(hba)) hba->clk_scaling.active_reqs--;Will be the
hba->clk_scaling.active_reqsvalue become abnormal by this flow?
Yes, it may undershoot. Actually the logic in __ufshcd_transfer_req_compl() should be updated - clk_scaling.active_reqs should be updated only when there are cmds (scsi or query) to complete. Here is not the only place which can cause a undershoot. We can prevent the undershoot with below check.
if (ufshcd_is_clkscaling_supported(hba) &&
hba->clk_scaling.active_reqs > 0)
hba->clk_scaling.active_reqs--;
Thanks,
Can Guo.
Quoted 34 lines
Thanks,
Stanley ChuQuoted 31 lines
drivers/scsi/ufs/ufshcd.c +5
-0+ } +spin_unlock_irqrestore (host->host_lock, flags); + goto out; + } +/* Skip task abort in case previous aborts failed and report failure */ if (lrbp->req_abort_skip)drivers/scsi/ufs/ufshcd.c +0
-0err = -EIO ;drivers/scsi/ufs/ufshcd.h +0
-0@@ -163,6 +163,7 @@ struct ufs_pm_lvl_states { * @crypto_key_slot: the key slot to use for inline crypto (-1 if none) * @data_unit_num: the data unit number for the first block forinline crypto
* @req_abort_skip: skip request abort task flag
+ * @in_use: indicates that this lrb is still in use */
structufshcd_lrb{drivers/scsi/ufs/ufshcd.h +1
-0struct utp_transfer_req_desc *utr_descriptor_ptr;@@ -192,6 +193,7 @@ struct ufshcd_lrb {#endif bool req_abort_skip; +bool in_use; };/**
PATCH v5 3/3 scsi: ufs: Print host regs in IRQ handler when AH8 error happens
In reply to Can GuoWhen AH8 error happens, all the regs and states are dumped in err handler. Sometime we need to look into host regs right after AH8 error happens, which is before leaving the IRQ handler.
--- drivers/scsi/ufs/ufshcd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
drivers/scsi/ufs/ufshcd.c +2 -1
@@ -6057,7 +6057,8 @@ static irqreturn_t ufshcd_check_errors(struct ufs_hba *hba) hba->saved_uic_err |= hba->uic_error;/* dump controller state before resetting */ -if ((hba->saved_err & (INT_FATAL_ERRORS )) || +if ((hba->saved_err & + (INT_FATAL_ERRORS |UFSHCD_UIC_HIBERN8_MASK )) || (hba->saved_uic_err && (hba->saved_uic_err !=UFSHCD_UIC_PA_GENERIC_ERROR ))) { dev_err(hba->dev, "%s: saved_err 0x%x saved_uic_err 0x%x\n",
Signature · 1 line
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
Re: [PATCH V5 3/3] scsi: ufs: Print host regs in IRQ handler when AH8 error happens
Quoted 8 lines · Can Guo
When AH8 error happens, all the regs and states are dumped in err handler. Sometime we need to look into host regs right after AH8 error happens, which is before leaving the IRQ handler.
Reviewed-by Bao D. Nguyen <[email protected]>Reviewed-by Asutosh Das <[email protected]>Reviewed-by Hongwu Su<[email protected]>Signed-off-by Can Guo <[email protected]>