6.1-stable review patch. If anyone has any objections, please let me know.
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From: Damien Le Moal dlemoal@kernel.org
[ Upstream commit 0a8589055936d8feb56477123a8373ac634018fa ]
During system resume, ata_port_pm_resume() triggers ata EH to 1) Resume the controller 2) Reset and rescan the ports 3) Revalidate devices This EH execution is started asynchronously from ata_port_pm_resume(), which means that when sd_resume() is executed, none or only part of the above processing may have been executed. However, sd_resume() issues a START STOP UNIT to wake up the drive from sleep mode. This command is translated to ATA with ata_scsi_start_stop_xlat() and issued to the device. However, depending on the state of execution of the EH process and revalidation triggerred by ata_port_pm_resume(), two things may happen: 1) The START STOP UNIT fails if it is received before the controller has been reenabled at the beginning of the EH execution. This is visible with error messages like:
ata10.00: device reported invalid CHS sector 0 sd 9:0:0:0: [sdc] Start/Stop Unit failed: Result: hostbyte=DID_OK driverbyte=DRIVER_OK sd 9:0:0:0: [sdc] Sense Key : Illegal Request [current] sd 9:0:0:0: [sdc] Add. Sense: Unaligned write command sd 9:0:0:0: PM: dpm_run_callback(): scsi_bus_resume+0x0/0x90 returns -5 sd 9:0:0:0: PM: failed to resume async: error -5
2) The START STOP UNIT command is received while the EH process is on-going, which mean that it is stopped and must wait for its completion, at which point the command is rather useless as the drive is already fully spun up already. This case results also in a significant delay in sd_resume() which is observable by users as the entire system resume completion is delayed.
Given that ATA devices will be woken up by libata activity on resume, sd_resume() has no need to issue a START STOP UNIT command, which solves the above mentioned problems. Do not issue this command by introducing the new scsi_device flag no_start_on_resume and setting this flag to 1 in ata_scsi_dev_config(). sd_resume() is modified to issue a START STOP UNIT command only if this flag is not set.
Reported-by: Paul Ausbeck paula@soe.ucsc.edu Closes: https://bugzilla.kernel.org/show_bug.cgi?id=215880 Fixes: a19a93e4c6a9 ("scsi: core: pm: Rely on the device driver core for async power management") Signed-off-by: Damien Le Moal dlemoal@kernel.org Tested-by: Tanner Watkins dalzot@gmail.com Tested-by: Paul Ausbeck paula@soe.ucsc.edu Reviewed-by: Hannes Reinecke hare@suse.de Reviewed-by: Bart Van Assche bvanassche@acm.org Stable-dep-of: 99398d2070ab ("scsi: sd: Do not issue commands to suspended disks on shutdown") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/ata/libata-scsi.c | 7 +++++++ drivers/scsi/sd.c | 9 ++++++--- include/scsi/scsi_device.h | 1 + 3 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index d28628b964e29..9c8dd9f86cbb3 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -1081,7 +1081,14 @@ int ata_scsi_dev_config(struct scsi_device *sdev, struct ata_device *dev) } } else { sdev->sector_size = ata_id_logical_sector_size(dev->id); + /* + * Stop the drive on suspend but do not issue START STOP UNIT + * on resume as this is not necessary and may fail: the device + * will be woken up by ata_port_pm_resume() with a port reset + * and device revalidation. + */ sdev->manage_start_stop = 1; + sdev->no_start_on_resume = 1; }
/* diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index e934779bf05c8..5bfca49415113 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -3718,7 +3718,7 @@ static int sd_suspend_runtime(struct device *dev) static int sd_resume(struct device *dev) { struct scsi_disk *sdkp = dev_get_drvdata(dev); - int ret; + int ret = 0;
if (!sdkp) /* E.g.: runtime resume at the start of sd_probe() */ return 0; @@ -3726,8 +3726,11 @@ static int sd_resume(struct device *dev) if (!sdkp->device->manage_start_stop) return 0;
- sd_printk(KERN_NOTICE, sdkp, "Starting disk\n"); - ret = sd_start_stop_device(sdkp, 1); + if (!sdkp->device->no_start_on_resume) { + sd_printk(KERN_NOTICE, sdkp, "Starting disk\n"); + ret = sd_start_stop_device(sdkp, 1); + } + if (!ret) opal_unlock_from_suspend(sdkp->opal_dev); return ret; diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 006858ed04e8c..9fdc77db3a2a8 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -193,6 +193,7 @@ struct scsi_device { unsigned no_start_on_add:1; /* do not issue start on add */ unsigned allow_restart:1; /* issue START_UNIT in error handler */ unsigned manage_start_stop:1; /* Let HLD (sd) manage start/stop */ + unsigned no_start_on_resume:1; /* Do not issue START_STOP_UNIT on resume */ unsigned start_stop_pwr_cond:1; /* Set power cond. in START_STOP_UNIT */ unsigned no_uld_attach:1; /* disable connecting to upper level drivers */ unsigned select_no_atn:1;