Patch "libata: Fall back to unqueued READ LOG EXT if the DMA variant fails" has been added to the 4.1-stable tree

This is a note to let you know that I've just added the patch titled

libata: Fall back to unqueued READ LOG EXT if the DMA variant fails

to the 4.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
libata-fall-back-to-unqueued-read-log-ext-if-the-dma-variant-fails.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: "Martin K. Petersen" <[email protected]>
Date: Mon, 4 May 2015 21:54:21 -0400
Subject: libata: Fall back to unqueued READ LOG EXT if the DMA variant fails

From: "Martin K. Petersen" <[email protected]>

commit 5d3abf8ff67f49271a42c0f7fa4f20f9e046bf0e upstream.

Some devices advertise support for the READ/WRITE LOG DMA EXT commands but fail when we try to issue them. This can lead to queued TRIM being unintentionally disabled since the relevant feature flag is located in a general purpose log page.

Fall back to unqueued READ LOG EXT if the DMA variant fails while reading a log page.

---
 drivers/ata/libata-eh.c |   12 +++++++++++-
 include/linux/libata.h  |    1 +
 2 files changed, 12 insertions(+), 1 deletion(-)

@@ -1507,13 +1507,17 @@ unsigned int ata_read_log_page(struct at
 {
 	struct ata_taskfile tf;
 	unsigned int err_mask;
+	bool dma = false;
 
 	DPRINTK("read log page - log 0x%x, page 0x%x\n", log, page);
 
+retry:
 	ata_tf_init(dev, &tf);
-	if (dev->dma_mode && ata_id_has_read_log_dma_ext(dev->id)) {
+	if (dev->dma_mode && ata_id_has_read_log_dma_ext(dev->id) &&
+	    !(dev->horkage & ATA_HORKAGE_NO_NCQ_LOG)) {
 		tf.command = ATA_CMD_READ_LOG_DMA_EXT;
 		tf.protocol = ATA_PROT_DMA;
+		dma = true;
 	} else {
 		tf.command = ATA_CMD_READ_LOG_EXT;
 		tf.protocol = ATA_PROT_PIO;

@@ -1527,6 +1531,12 @@ unsigned int ata_read_log_page(struct at
 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
 				     buf, sectors * ATA_SECT_SIZE, 0);
 
+	if (err_mask && dma) {
+		dev->horkage |= ATA_HORKAGE_NO_NCQ_LOG;
+		ata_dev_warn(dev, "READ LOG DMA EXT failed, trying unqueued\n");
+		goto retry;
+	}
+
 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
 	return err_mask;
 }

@@ -431,6 +431,7 @@ enum {
 	ATA_HORKAGE_NOLPM	= (1 << 20),	/* don't use LPM */
 	ATA_HORKAGE_WD_BROKEN_LPM = (1 << 21),	/* some WDs have broken LPM */
 	ATA_HORKAGE_ZERO_AFTER_TRIM = (1 << 22),/* guarantees zero after trim */
+	ATA_HORKAGE_NO_NCQ_LOG	= (1 << 23),	/* don't use NCQ for log read */
 
 	 /* DMA mask for user DMA control: User visible values; DO NOT
 	    renumber */

Patches currently in stable-queue which might be from [email protected] are

queue-4.1/libata-fall-back-to-unqueued-read-log-ext-if-the-dma-variant-fails.patch queue-4.1/libata-expose-trim-capability-in-sysfs.patch queue-4.1/libata-do-not-blacklist-micron-m500dc.patch queue-4.1/libata-do-not-blacklist-m510dc.patch

Hi

This patch, as part of the current -stable queue-4.1 introduces a regression for me on an ivy-bridge Asus P8H77-M PRO[1] mainboard using a Toshiba DT01ACA3 attached. When trying to boot, the system stops with a high spinning loop (and many supressed printks) of

ata1.00: READ LOG DMA EXT failed, trying unqueued

while still being in the initramfs code.

00:1f.2 SATA controller [0106]: Intel Corporation 7 Series/C210 Series Chipset Family 6-port SATA Controller [AHCI mode] [8086:1e02] (rev 04) (prog-if 01 [AHCI 1.0])
Subsystem: ASUSTeK Computer Inc. P8 series motherboard [1043:84ca]
Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Latency: 0
Interrupt: pin B routed to IRQ 30
Region 0: I/O ports at f0b0 [size=8]
Region 1: I/O ports at f0a0 [size=4]
Region 2: I/O ports at f090 [size=8]
Region 3: I/O ports at f080 [size=4]
Region 4: I/O ports at f060 [size=32]
Region 5: Memory at f7f16000 (32-bit, non-prefetchable) [size=2K]
Capabilities: [80] MSI: Enable+ Count=1/1 Maskable- 64bit-
Address: fee00398 Data: 0000
Capabilities: [70] Power Management version 3
Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot+,D3cold-)
Status: D0 NoSoftRst+ PME-Enable- DSel=0 DScale=0 PME-
Capabilities: [a8] SATA HBA v1.0 BAR4 Offset=00000004
Capabilities: [b0] PCI Advanced Features
AFCap: TP+ FLR+
AFCtrl: FLR-
AFStatus: TP-
Kernel driver in use: ahci

$ lsscsi 
[0:0:0:0]    disk    ATA      Samsung SSD 840  6B0Q  /dev/sda 
[1:0:0:0]    disk    ATA      TOSHIBA DT01ACA3 ABB0  /dev/sdb 
[2:0:0:0]    disk    ATA      SAMSUNG HD204UI  0001  /dev/sdc 
[3:0:0:0]    disk    ATA      SAMSUNG HD204UI  0001  /dev/sdd 
[4:0:0:0]    disk    ATA      ST3000DM001-1CH1 CC24  /dev/sde 
[5:0:0:0]    disk    ATA      TOSHIBA DT01ACA3 ABB0  /dev/sdf

Reverting only this patch from the current queue-4.1, and fixing up the trivial merge conflicts this introduces for the subsequent patches

libata-add-ata_horkage_max_sec_1024-to-revert-back-to-previous-max_sectors-limit.patch libata-add-ata_horkage_notrim.patch

fixes the problem for me.

Regards
Stefan Lippers-Hollmann

[1] http://www.asus.com/Motherboards/P8H77M_PRO

Greg,

Please queue eab6ee1ce3c4.

Martin K. Petersen	Oracle Linux Engineering

commit eab6ee1ce3c4678224d70338134f7a02005768cb
Author: Martin K. Petersen <[email protected]>
Date:   Tue May 19 19:44:17 2015 -0400

    libata: Fix regression when the NCQ Send and Receive log page is absent
    
    Commit 5d3abf8ff67f ("libata: Fall back to unqueued READ LOG EXT if
    the DMA variant fails") allowed us to fall back to the unqueued READ
    LOG variant if the queued version failed. However, if the device did
    not support the page at all we would end up looping due to a merge
    snafu.
    
    Ensure we only take the fallback path once.
    
    Signed-off-by: Martin K. Petersen <[email protected]>
    Reported-by: Sergey Senozhatsky <[email protected]>
    Tested-by: Sergey Senozhatsky <[email protected]>
    Signed-off-by: Tejun Heo <[email protected]>

index 2893563d0537..2b370ee0ae86 100644
@@ -1521,6 +1521,7 @@ retry:
 	} else {
 		tf.command = ATA_CMD_READ_LOG_EXT;
 		tf.protocol = ATA_PROT_PIO;
+		dma = false;
 	}
 	tf.lbal = log;
 	tf.lbam = page;

Now applied to the 4.1-stable queue, thanks.

greg k-h

Hi

[...]

Thanks, it's working now.

Regards
Stefan Lippers-Hollmann