Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-17 08:31:39 +00:00
Code Issues Packages Projects Releases Wiki Activity

scsi: ufs: Fix runtime PM messages never-ending cycle

Browse Source 
Kernel messages produced during runtime PM can cause a never-ending cycle
because user space utilities (e.g. journald or rsyslog) write the messages
back to storage, causing runtime resume, more messages, and so on.

Messages that tell of things that are expected to happen, are arguably
unnecessary, so suppress them.

UFS driver messages are changes to from dev_err() to dev_dbg() which means
they will not display unless activated by dynamic debug of building with
-DDEBUG.

sdev->silence_suspend is set to skip messages from sd_suspend_common()
"Synchronizing SCSI cache", "Stopping disk" and scsi_report_sense()
"Power-on or device reset occurred" message (Note, that message appears
when the LUN is accessed after runtime PM, not during runtime PM)

 Example messages from Ubuntu 21.10:

 $ dmesg | tail
 [ 1620.380071] ufshcd 0000:00:12.5: ufshcd_print_pwr_info:[RX, TX]: gear=[1, 1], lane[1, 1], pwr[SLOWAUTO_MODE, SLOWAUTO_MODE], rate = 0
 [ 1620.408825] ufshcd 0000:00:12.5: ufshcd_print_pwr_info:[RX, TX]: gear=[4, 4], lane[2, 2], pwr[FAST MODE, FAST MODE], rate = 2
 [ 1620.409020] ufshcd 0000:00:12.5: ufshcd_find_max_sup_active_icc_level: Regulator capability was not set, actvIccLevel=0
 [ 1620.409524] sd 0:0:0:0: Power-on or device reset occurred
 [ 1622.938794] sd 0:0:0:0: [sda] Synchronizing SCSI cache
 [ 1622.939184] ufs_device_wlun 0:0:0:49488: Power-on or device reset occurred
 [ 1625.183175] ufshcd 0000:00:12.5: ufshcd_print_pwr_info:[RX, TX]: gear=[1, 1], lane[1, 1], pwr[SLOWAUTO_MODE, SLOWAUTO_MODE], rate = 0
 [ 1625.208041] ufshcd 0000:00:12.5: ufshcd_print_pwr_info:[RX, TX]: gear=[4, 4], lane[2, 2], pwr[FAST MODE, FAST MODE], rate = 2
 [ 1625.208311] ufshcd 0000:00:12.5: ufshcd_find_max_sup_active_icc_level: Regulator capability was not set, actvIccLevel=0
 [ 1625.209035] sd 0:0:0:0: Power-on or device reset occurred

Note for stable: depends on patch "scsi: core: sd: Add silence_suspend flag
to suppress some PM messages".

Link: https://lore.kernel.org/r/20220228113652.970857-3-adrian.hunter@intel.com
Cc: stable@vger.kernel.org
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Adrian Hunter 2022-02-28 13:36:52 +02:00 committed by Martin K. Petersen
parent af4edb1d50
commit 71bb9ab6e3
1 changed files with 19 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
drivers/scsi/ufs/ufshcd.c
View File

@ -583,7 +583,12 @@ static void ufshcd_print_pwr_info(struct ufs_hba *hba)
"INVALID MODE",
};
dev_err(hba->dev, "%s:[RX, TX]: gear=[%d, %d], lane[%d, %d], pwr[%s, %s], rate = %d\n",
/*
* Using dev_dbg to avoid messages during runtime PM to avoid
* never-ending cycles of messages written back to storage by user space
* causing runtime resume, causing more messages and so on.
*/
dev_dbg(hba->dev, "%s:[RX, TX]: gear=[%d, %d], lane[%d, %d], pwr[%s, %s], rate = %d\n",
__func__,
hba->pwr_info.gear_rx, hba->pwr_info.gear_tx,
hba->pwr_info.lane_rx, hba->pwr_info.lane_tx,
@ -5022,6 +5027,12 @@ static int ufshcd_slave_configure(struct scsi_device *sdev)
pm_runtime_get_noresume(&sdev->sdev_gendev);
else if (ufshcd_is_rpm_autosuspend_allowed(hba))
sdev->rpm_autosuspend = 1;
/*
* Do not print messages during runtime PM to avoid never-ending cycles
* of messages written back to storage by user space causing runtime
* resume, causing more messages and so on.
*/
sdev->silence_suspend = 1;
ufshcd_crypto_register(hba, q);
@ -7384,7 +7395,13 @@ static u32 ufshcd_find_max_sup_active_icc_level(struct ufs_hba *hba,
if (!hba->vreg_info.vcc || !hba->vreg_info.vccq ||
!hba->vreg_info.vccq2) {
dev_err(hba->dev,
/*
* Using dev_dbg to avoid messages during runtime PM to avoid
* never-ending cycles of messages written back to storage by
* user space causing runtime resume, causing more messages and
* so on.
*/
dev_dbg(hba->dev,
"%s: Regulator capability was not set, actvIccLevel=%d",
__func__, icc_level);
goto out;