From 71bb9ab6e3511b7bb98678a19eb8cf1ccbf3ca2f Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Mon, 28 Feb 2022 13:36:52 +0200 Subject: [PATCH] scsi: ufs: Fix runtime PM messages never-ending cycle 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 Signed-off-by: Martin K. Petersen --- drivers/scsi/ufs/ufshcd.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 40be73a..59c5135 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -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; -- 2.7.4