diff mbox series

[v5,5/8] scsi: ufs: Fix ufshcd_hold() caused scheduling while atomic

Message ID 1580721472-10784-6-git-send-email-cang@codeaurora.org (mailing list archive)
State Superseded
Headers show
Series UFS driver general fixes bundle 4 | expand

Commit Message

Can Guo Feb. 3, 2020, 9:17 a.m. UTC 
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.

Signed-off-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
---
 drivers/scsi/ufs/ufshcd.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Bean Huo Feb. 3, 2020, 10:07 p.m. UTC | #1 
> Signed-off-by: Can Guo <cang@codeaurora.org>
> Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
> Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Stanley Chu Feb. 4, 2020, 6:26 a.m. UTC | #2 
On Mon, 2020-02-03 at 01:17 -0800, Can Guo wrote:
> 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.
> 
> Signed-off-by: Can Guo <cang@codeaurora.org>
> Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
> Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>

Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
diff mbox series

Patch

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index bbc2607..e8f7f9d 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1518,6 +1518,11 @@  int ufshcd_hold(struct ufs_hba *hba, bool async)
 		 */
 		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);