Instead of downgrade_write(), extend the ufshcd_down_write() to cover ufshcd_wb_toggle() because ufshcd_down_write() now supports nesting ufshcd_down_read() but down_read() nested within down_read() can deadlock. Reported-by: Can Guo <cang@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/all/fbc4d03a07f03fe4fbe697813111471f@xxxxxxxxxxxxxx Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx> --- drivers/scsi/ufs/ufshcd.c | 12 +++--------- drivers/scsi/ufs/ufshcd.h | 6 ------ 2 files changed, 3 insertions(+), 15 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 3912b74d50ae..64ac9e48c4d7 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -1192,12 +1192,9 @@ static int ufshcd_clock_scaling_prepare(struct ufs_hba *hba) return ret; } -static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba, bool writelock) +static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba) { - if (writelock) - ufshcd_up_write(hba); - else - ufshcd_up_read(hba); + ufshcd_up_write(hba); ufshcd_scsi_unblock_requests(hba); ufshcd_release(hba); } @@ -1214,7 +1211,6 @@ static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba, bool writelock) static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up) { int ret = 0; - bool is_writelock = true; ret = ufshcd_clock_scaling_prepare(hba); if (ret) @@ -1244,12 +1240,10 @@ static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up) } /* Enable Write Booster if we have scaled up else disable it */ - ufshcd_downgrade_write(hba); - is_writelock = false; ufshcd_wb_toggle(hba, scale_up); out_unprepare: - ufshcd_clock_scaling_unprepare(hba, is_writelock); + ufshcd_clock_scaling_unprepare(hba); return ret; } diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index 74891947bb34..47f81eae178c 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -1457,10 +1457,4 @@ static inline void ufshcd_up_write(struct ufs_hba *hba) up_write(&hba->host_rw_sem); } -static inline void ufshcd_downgrade_write(struct ufs_hba *hba) -{ - hba->excl_task = NULL; - downgrade_write(&hba->host_rw_sem); -} - #endif /* End of Header */ -- 2.25.1
