From: Can Guo cang@codeaurora.org
commit c63d6099a7959ecc919b2549dc6b71f53521f819 upstream.
The async version of ufshcd_hold(async == true), which is only called in queuecommand path as for now, is expected to work in atomic context, thus it should not sleep or schedule out. When it runs into the condition that clocks are ON but link is still in hibern8 state, it should bail out without flushing the clock ungate work.
Fixes: f2a785ac2312 ("scsi: ufshcd: Fix race between clk scaling and ungate work") Link: https://lore.kernel.org/r/1581392451-28743-6-git-send-email-cang@codeaurora.... Reviewed-by: Hongwu Su hongwus@codeaurora.org Reviewed-by: Asutosh Das asutoshd@codeaurora.org Reviewed-by: Bean Huo beanhuo@micron.com Reviewed-by: Stanley Chu stanley.chu@mediatek.com Signed-off-by: Can Guo cang@codeaurora.org Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/scsi/ufs/ufshcd.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -595,6 +595,11 @@ start: */ if (ufshcd_can_hibern8_during_gating(hba) && ufshcd_is_link_hibern8(hba)) { + if (async) { + rc = -EAGAIN; + hba->clk_gating.active_reqs--; + break; + } spin_unlock_irqrestore(hba->host->host_lock, flags); flush_work(&hba->clk_gating.ungate_work); spin_lock_irqsave(hba->host->host_lock, flags);