Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 10/40] scsi: ufs: Fix ufshcd_hold() caused scheduling while atomic | Date | Mon, 20 Apr 2020 14:39:20 +0200 |
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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 @@ -1563,6 +1563,11 @@ 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);
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