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boot_constraint: Add constraints for earlycon on dragonboard 410c

PATCH In review Sai Prakash Ranjan 2 participants 3 messages Nov 16, 2018

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Sai Prakash Ranjan

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#0 lore raw

PATCH 1/1 boot_constraint: Add constraints for earlycon on dragonboard 410c

iface clock is shared with other drivers, which may reconfigure this before the serial driver comes up. This may lead to crashes like the one below where GCC_BLSP1_AHB_CLK is same across multiple drivers like bam dma.

<0>[    3.164471] Internal error: synchronous external abort: 96000010 [#1] PREEMPT SMP
<4>[    3.164479] Modules linked in:
<4>[    3.164495] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc8-00008-ge033b9909fff-dirty #175
<4>[    3.164501] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
<4>[    3.164508] pstate: 40000085 (nZcv daIf -PAN -UAO)
<4>[    3.164514] pc : msm_read.isra.2+0x20/0x50
<4>[    3.164520] lr : msm_read.isra.2+0x1c/0x50
<4>[    3.164526] sp : ffff000008033a50
<4>[    3.164531] x29: ffff000008033a50 x28: ffff000009486018
<4>[    3.164548] x27: 0000000000000001 x26: ffff7dfffe7ff070
<4>[    3.164565] x25: 0000000000000034 x24: ffff000009486000
<4>[    3.164582] x23: 0000000000000000 x22: ffff00000978e190
<4>[    3.164599] x21: ffff0000095e8228 x20: 0000000000000034
<4>[    3.164616] x19: ffff7dfffe7ff008 x18: ffffffffffffffff
<4>[    3.164632] x17: 0000000000000000 x16: 0000000000000000
<4>[    3.164649] x15: ffff0000094a96c8 x14: ffff00008978e6bf
<4>[    3.164666] x13: ffff00000978e6cd x12: 0000000000000038
<4>[    3.164683] x11: ffff0000094c6000 x10: 0000000000000c24
<4>[    3.164699] x9 : ffff80003c89b400 x8 : ffff000008033970
<4>[    3.164716] x7 : ffff80000eb04100 x6 : 00000000000af304
<4>[    3.164732] x5 : 0000000000000c40 x4 : ffff80003c06f000
<4>[    3.164750] x3 : ffff80003c89b498 x2 : 0000000000000000
<4>[    3.164766] x1 : ffff80003ca68000 x0 : 0000000000000800
<0>[    3.164785] Process swapper/0 (pid: 1, stack limit = 0x(____ptrval____))
<4>[    3.164791] Call trace:
<4>[    3.164797]  msm_read.isra.2+0x20/0x50
<4>[    3.164804]  msm_reset_dm_count+0x44/0x80
<4>[    3.164810]  __msm_console_write+0x1c8/0x1d0
<4>[    3.164816]  msm_serial_early_write_dm+0x3c/0x50
<4>[    3.164823]  console_unlock.part.6+0x468/0x528
<4>[    3.164829]  vprintk_emit+0x210/0x218
<4>[    3.164835]  vprintk_default+0x48/0x58
<4>[    3.164841]  vprintk_func+0xf0/0x1c0
<4>[    3.164847]  printk+0x74/0x94
<4>[    3.164853]  sci_init+0x24/0x3c
<4>[    3.164859]  do_one_initcall+0x54/0x248
<4>[    3.164866]  kernel_init_freeable+0x210/0x378
<4>[    3.164872]  kernel_init+0x18/0x118
<4>[    3.164878]  ret_from_fork+0x10/0x1c
<0>[    3.164884] Code: aa1e03e0 8b214273 97e616f7 d503201f (b9400260)
Link https://lore.kernel.org/lkml/1cae8f10-55f5-20ce-9105-30af6f88bd6e at codeaurora.org/
Signed-off-by Sai Prakash Ranjan <[email protected]>

---

This is purely dependent on boot constraint subsystem by Viresh.

Link https://lore.kernel.org/lkml/cover.1519380923.git.viresh.kumar at linaro.org/
---
 drivers/soc/qcom/boot_constraint.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
drivers/soc/qcom/boot_constraint.c +15 -0
index ca01eb50d9a9..c4e580a118f0 100644
@@ -49,6 +49,10 @@ static struct dev_boot_constraint_supply_info vddio_info = {
 	.name = "vddio"
 };
 
+static struct dev_boot_constraint_clk_info uart_iface_clk_info = {
+	.name = "iface",
+};
+
 static struct dev_boot_constraint constraints_mdss[] = {
 	{
 		.type = DEV_BOOT_CONSTRAINT_PM,

@@ -92,6 +96,13 @@ static struct dev_boot_constraint constraints_dsi[] = {
 	},
 };
 
+static struct dev_boot_constraint constraints_uart[] = {
+	{
+		.type = DEV_BOOT_CONSTRAINT_CLK,
+		.data = &uart_iface_clk_info,
+	},
+};
+
 static struct dev_boot_constraint_of constraints[] = {
 	{
 		.compat = "qcom,mdss",

@@ -105,6 +116,10 @@ static struct dev_boot_constraint_of constraints[] = {
 		.compat = "qcom,mdss-dsi-ctrl",
 		.constraints = constraints_dsi,
 		.count = ARRAY_SIZE(constraints_dsi),
+	}, {
+		.compat = "qcom,msm-uartdm-v1.4",
+		.constraints = constraints_uart,
+		.count = ARRAY_SIZE(constraints_uart),
 	},
 };
Signature · 2 lines
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
#1 lore raw

Hi,

Quoted 49 lines · Sai Prakash Ranjan

iface clock is shared with other drivers, which may reconfigure this before the serial driver comes up. This may lead to crashes like the one below where GCC_BLSP1_AHB_CLK is same across multiple drivers like bam dma.

<0>[    3.164471] Internal error: synchronous external abort: 96000010 [#1] PREEMPT SMP
<4>[    3.164479] Modules linked in:
<4>[    3.164495] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc8-00008-ge033b9909fff-dirty #175
<4>[    3.164501] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
<4>[    3.164508] pstate: 40000085 (nZcv daIf -PAN -UAO)
<4>[    3.164514] pc : msm_read.isra.2+0x20/0x50
<4>[    3.164520] lr : msm_read.isra.2+0x1c/0x50
<4>[    3.164526] sp : ffff000008033a50
<4>[    3.164531] x29: ffff000008033a50 x28: ffff000009486018
<4>[    3.164548] x27: 0000000000000001 x26: ffff7dfffe7ff070
<4>[    3.164565] x25: 0000000000000034 x24: ffff000009486000
<4>[    3.164582] x23: 0000000000000000 x22: ffff00000978e190
<4>[    3.164599] x21: ffff0000095e8228 x20: 0000000000000034
<4>[    3.164616] x19: ffff7dfffe7ff008 x18: ffffffffffffffff
<4>[    3.164632] x17: 0000000000000000 x16: 0000000000000000
<4>[    3.164649] x15: ffff0000094a96c8 x14: ffff00008978e6bf
<4>[    3.164666] x13: ffff00000978e6cd x12: 0000000000000038
<4>[    3.164683] x11: ffff0000094c6000 x10: 0000000000000c24
<4>[    3.164699] x9 : ffff80003c89b400 x8 : ffff000008033970
<4>[    3.164716] x7 : ffff80000eb04100 x6 : 00000000000af304
<4>[    3.164732] x5 : 0000000000000c40 x4 : ffff80003c06f000
<4>[    3.164750] x3 : ffff80003c89b498 x2 : 0000000000000000
<4>[    3.164766] x1 : ffff80003ca68000 x0 : 0000000000000800
<0>[    3.164785] Process swapper/0 (pid: 1, stack limit = 0x(____ptrval____))
<4>[    3.164791] Call trace:
<4>[    3.164797]  msm_read.isra.2+0x20/0x50
<4>[    3.164804]  msm_reset_dm_count+0x44/0x80
<4>[    3.164810]  __msm_console_write+0x1c8/0x1d0
<4>[    3.164816]  msm_serial_early_write_dm+0x3c/0x50
<4>[    3.164823]  console_unlock.part.6+0x468/0x528
<4>[    3.164829]  vprintk_emit+0x210/0x218
<4>[    3.164835]  vprintk_default+0x48/0x58
<4>[    3.164841]  vprintk_func+0xf0/0x1c0
<4>[    3.164847]  printk+0x74/0x94
<4>[    3.164853]  sci_init+0x24/0x3c
<4>[    3.164859]  do_one_initcall+0x54/0x248
<4>[    3.164866]  kernel_init_freeable+0x210/0x378
<4>[    3.164872]  kernel_init+0x18/0x118
<4>[    3.164878]  ret_from_fork+0x10/0x1c
<0>[    3.164884] Code: aa1e03e0 8b214273 97e616f7 d503201f (b9400260)
Link https://lore.kernel.org/lkml/1cae8f10-55f5-20ce-9105-30af6f88bd6e at codeaurora.org/
Signed-off-by Sai Prakash Ranjan <[email protected]>
Quoted 8 lines

---

This is purely dependent on boot constraint subsystem by Viresh.

Link https://lore.kernel.org/lkml/cover.1519380923.git.viresh.kumar at linaro.org/
---
 drivers/soc/qcom/boot_constraint.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

Nice to see that the new subsystem has fixed your issue as well and thanks for the patch. I am afraid though that this patch isn't going to get merged anywhere as the subsystem isn't merged yet as Greg wasn't too confident [1] about it. We are looking for more use-cases apart from earlycon and clcd.

Thanks.

--
viresh

[1] lore.kernel.org/lkml/20180323150420.GA21152 at kroah.com

author
#2 lore raw
Quoted 61 lines · Viresh Kumar

Hi,

Quoted 49 lines · Sai Prakash Ranjan

iface clock is shared with other drivers, which may reconfigure this before the serial driver comes up. This may lead to crashes like the one below where GCC_BLSP1_AHB_CLK is same across multiple drivers like bam dma.

<0>[    3.164471] Internal error: synchronous external abort: 96000010 [#1] PREEMPT SMP
<4>[    3.164479] Modules linked in:
<4>[    3.164495] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc8-00008-ge033b9909fff-dirty #175
<4>[    3.164501] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT)
<4>[    3.164508] pstate: 40000085 (nZcv daIf -PAN -UAO)
<4>[    3.164514] pc : msm_read.isra.2+0x20/0x50
<4>[    3.164520] lr : msm_read.isra.2+0x1c/0x50
<4>[    3.164526] sp : ffff000008033a50
<4>[    3.164531] x29: ffff000008033a50 x28: ffff000009486018
<4>[    3.164548] x27: 0000000000000001 x26: ffff7dfffe7ff070
<4>[    3.164565] x25: 0000000000000034 x24: ffff000009486000
<4>[    3.164582] x23: 0000000000000000 x22: ffff00000978e190
<4>[    3.164599] x21: ffff0000095e8228 x20: 0000000000000034
<4>[    3.164616] x19: ffff7dfffe7ff008 x18: ffffffffffffffff
<4>[    3.164632] x17: 0000000000000000 x16: 0000000000000000
<4>[    3.164649] x15: ffff0000094a96c8 x14: ffff00008978e6bf
<4>[    3.164666] x13: ffff00000978e6cd x12: 0000000000000038
<4>[    3.164683] x11: ffff0000094c6000 x10: 0000000000000c24
<4>[    3.164699] x9 : ffff80003c89b400 x8 : ffff000008033970
<4>[    3.164716] x7 : ffff80000eb04100 x6 : 00000000000af304
<4>[    3.164732] x5 : 0000000000000c40 x4 : ffff80003c06f000
<4>[    3.164750] x3 : ffff80003c89b498 x2 : 0000000000000000
<4>[    3.164766] x1 : ffff80003ca68000 x0 : 0000000000000800
<0>[    3.164785] Process swapper/0 (pid: 1, stack limit = 0x(____ptrval____))
<4>[    3.164791] Call trace:
<4>[    3.164797]  msm_read.isra.2+0x20/0x50
<4>[    3.164804]  msm_reset_dm_count+0x44/0x80
<4>[    3.164810]  __msm_console_write+0x1c8/0x1d0
<4>[    3.164816]  msm_serial_early_write_dm+0x3c/0x50
<4>[    3.164823]  console_unlock.part.6+0x468/0x528
<4>[    3.164829]  vprintk_emit+0x210/0x218
<4>[    3.164835]  vprintk_default+0x48/0x58
<4>[    3.164841]  vprintk_func+0xf0/0x1c0
<4>[    3.164847]  printk+0x74/0x94
<4>[    3.164853]  sci_init+0x24/0x3c
<4>[    3.164859]  do_one_initcall+0x54/0x248
<4>[    3.164866]  kernel_init_freeable+0x210/0x378
<4>[    3.164872]  kernel_init+0x18/0x118
<4>[    3.164878]  ret_from_fork+0x10/0x1c
<0>[    3.164884] Code: aa1e03e0 8b214273 97e616f7 d503201f (b9400260)
Link https://lore.kernel.org/lkml/1cae8f10-55f5-20ce-9105-30af6f88bd6e at codeaurora.org/
Signed-off-by Sai Prakash Ranjan <[email protected]>
Quoted 8 lines

---

This is purely dependent on boot constraint subsystem by Viresh.

Link https://lore.kernel.org/lkml/cover.1519380923.git.viresh.kumar at linaro.org/
---
  drivers/soc/qcom/boot_constraint.c | 15 +++++++++++++++
  1 file changed, 15 insertions(+)
Quoted 7 lines

Nice to see that the new subsystem has fixed your issue as well and thanks for the patch. I am afraid though that this patch isn't going to get merged anywhere as the subsystem isn't merged yet as Greg wasn't too confident [1] about it. We are looking for more use-cases apart from earlycon and clcd.

Hi Viresh,

Thanks for your time.

I wanted to get this patch out so that once we have enough use cases, maybe we can add this as well.

Thanks,
Sai

Signature · 2 lines
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation