[v4] usb: host: xhci-mtk: avoid runtime suspend when removing hcd

Commit Message

Macpaul Lin June 4, 2020, 3:01 a.m. UTC

When runtime suspend was enabled, runtime suspend might happen
when xhci is removing hcd. This might cause kernel panic when hcd
has been freed but runtime pm suspend related handle need to
reference it.

Signed-off-by: Macpaul Lin <[e-mail]>
Reviewed-by: Chunfeng Yun <[e-mail]>
Cc: [e-mail]
---
Changes for v3:
  - Replace better sequence for disabling the pm_runtime suspend.
Changes for v4:
  - Thanks for Sergei's review, typo in commit description has been corrected.

 drivers/usb/host/xhci-mtk.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Comments

Mathias Nyman June 4, 2020, 9:14 a.m. UTC | #1

On 4.6.2020 6.01, Macpaul Lin wrote:
> When runtime suspend was enabled, runtime suspend might happen
> when xhci is removing hcd. This might cause kernel panic when hcd
> has been freed but runtime pm suspend related handle need to
> reference it.
> 
> Signed-off-by: Macpaul Lin <[e-mail]>
> Reviewed-by: Chunfeng Yun <[e-mail]>
> Cc: [e-mail]
> ---
> Changes for v3:
>   - Replace better sequence for disabling the pm_runtime suspend.
> Changes for v4:
>   - Thanks for Sergei's review, typo in commit description has been corrected.
> 

Thanks, added to queue

-Mathias

Patch

diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index bfbdb3c..641d24e 100644
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -587,6 +587,9 @@  static int xhci_mtk_remove(struct platform_device *dev)
 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
 	struct usb_hcd  *shared_hcd = xhci->shared_hcd;
 
+	pm_runtime_put_noidle(&dev->dev);
+	pm_runtime_disable(&dev->dev);
+
 	usb_remove_hcd(shared_hcd);
 	xhci->shared_hcd = NULL;
 	device_init_wakeup(&dev->dev, false);
@@ -597,8 +600,6 @@  static int xhci_mtk_remove(struct platform_device *dev)
 	xhci_mtk_sch_exit(mtk);
 	xhci_mtk_clks_disable(mtk);
 	xhci_mtk_ldos_disable(mtk);
-	pm_runtime_put_sync(&dev->dev);
-	pm_runtime_disable(&dev->dev);
 
 	return 0;
 }