| From c63d6099a7959ecc919b2549dc6b71f53521f819 Mon Sep 17 00:00:00 2001 |
| From: Can Guo <cang@codeaurora.org> |
| Date: Mon, 10 Feb 2020 19:40:48 -0800 |
| Subject: scsi: ufs: Fix ufshcd_hold() caused scheduling while atomic |
| |
| 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.org |
| 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 |
| @@ -1539,6 +1539,11 @@ 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); |
