]> git.itanic.dy.fi Git - linux-stable/commit
usb: dwc3: debugfs: Resume dwc3 before accessing registers
authorUdipto Goswami <quic_ugoswami@quicinc.com>
Tue, 9 May 2023 14:48:36 +0000 (20:18 +0530)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 30 May 2023 11:57:53 +0000 (12:57 +0100)
commite35adb75fda5a6254f7cd232a704dde81206061b
tree40ea1dfc08e3d0f775093edd17beca7b14394974
parent66070f5b99954793fe1caa568ee3c0a0abccd6c1
usb: dwc3: debugfs: Resume dwc3 before accessing registers

commit 614ce6a2ea50068b45339257891e51e639ac9001 upstream.

When the dwc3 device is runtime suspended, various required clocks are in
disabled state and it is not guaranteed that access to any registers would
work. Depending on the SoC glue, a register read could be as benign as
returning 0 or be fatal enough to hang the system.

In order to prevent such scenarios of fatal errors, make sure to resume
dwc3 then allow the function to proceed.

Fixes: 72246da40f37 ("usb: Introduce DesignWare USB3 DRD Driver")
Cc: stable@vger.kernel.org #3.2: 30332eeefec8: debugfs: regset32: Add Runtime PM support
Signed-off-by: Udipto Goswami <quic_ugoswami@quicinc.com>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20230509144836.6803-1-quic_ugoswami@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/dwc3/debugfs.c