diff options
| author | Bart Van Assche <bvanassche@acm.org> | 2025-12-04 08:15:43 -1000 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2025-12-08 21:58:28 -0500 |
| commit | d2875b812b141d0c449541976d92c8d89b94ec72 (patch) | |
| tree | 8703f7afd41dfa04b0955fde2ce59b4d009611df /drivers/ufs | |
| parent | 14be351e5cd07349377010e457a58fac99201832 (diff) | |
scsi: ufs: core: Fix a deadlock in the frequency scaling code
Commit 08b12cda6c44 ("scsi: ufs: core: Switch to scsi_get_internal_cmd()")
accidentally introduced a deadlock in the frequency scaling code.
ufshcd_clock_scaling_unprepare() may submit a device management command
while SCSI command processing is blocked. The deadlock was introduced by
using the SCSI core for submitting device management commands
(scsi_get_internal_cmd() + blk_execute_rq()). Fix this deadlock by calling
blk_mq_unquiesce_tagset() before any device management commands are
submitted by ufshcd_clock_scaling_unprepare().
Fixes: 08b12cda6c44 ("scsi: ufs: core: Switch to scsi_get_internal_cmd()")
Reported-by: Manivannan Sadhasivam <mani@kernel.org>
Reported-by: Roger Shimizu <rosh@debian.org>
Closes: https://lore.kernel.org/linux-scsi/ehorjaflathzab5oekx2nae2zss5vi2r36yqkqsfjb2fgsifz2@yk3us5g3igow/
Tested-by: Roger Shimizu <rosh@debian.org>
Cc: Nitin Rawat <nitin.rawat@oss.qualcomm.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Reviewed-by: Nitin Rawat <nitin.rawat@oss.qualcomm.com>
Tested-by: Alexey Klimov <alexey.klimov@linaro.org> # RB5 board
Link: https://patch.msgid.link/20251204181548.1006696-1-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/ufs')
| -rw-r--r-- | drivers/ufs/core/ufshcd.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index 1837ae204d5e..80c0b49f30b0 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -1455,15 +1455,14 @@ out: static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba, int err) { up_write(&hba->clk_scaling_lock); + mutex_unlock(&hba->wb_mutex); + blk_mq_unquiesce_tagset(&hba->host->tag_set); + mutex_unlock(&hba->host->scan_mutex); /* Enable Write Booster if current gear requires it else disable it */ if (ufshcd_enable_wb_if_scaling_up(hba) && !err) ufshcd_wb_toggle(hba, hba->pwr_info.gear_rx >= hba->clk_scaling.wb_gear); - mutex_unlock(&hba->wb_mutex); - - blk_mq_unquiesce_tagset(&hba->host->tag_set); - mutex_unlock(&hba->host->scan_mutex); ufshcd_release(hba); } |