]> 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 11:44:06 +0000 (12:44 +0100)
commit33b6648d27b8db9deca0bdefeba9be755c9323c6
tree78c4b1e3a0452cdb0ab7bb06b668951ca7c52766
parent241491524ab01dc8c4946606867d764197c9d624
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