Hi,
On Mon, Sep 11, 2023, William Wu wrote:
> If we enable PM runtime auto suspend for dwc3 on rockchip
> platforms (e.g. RK3562), it allows the dwc3 controller to
> enter runtime suspend if usb cable detached and power off
> the power domain of the controller. When system resume, if
> the dwc3 already in runtime suspended, it Shouldn't access
> the dwc3 registers in dwc3_resume() because its power domain
> maybe power off.
>
> Test on RK3562 tablet, this patch can help to avoid kernel
> panic when accessing the dwc3 registers in dwc3_resume() if
> the dwc3 is in runtime suspended and it's power domain is
> power off.
The controller should be woken up before this step. Can you provide more
detail on what led to this?
e.g. some questions:
Who handles the waking up of the controller? Is it the phy driver? Is
the phy driver not detecting a resume? Or did the resume fail? Does this
occur consistently?
Thanks,
Thinh
>
> Kernel panic - not syncing: Asynchronous SError Interrupt
> Hardware name: Rockchip RK3562 RK817 TABLET LP4 Board (DT)
> Call trace:
> dump_backtrace.cfi_jt+0x0/0x8
> dump_stack_lvl+0xc0/0x13c
> panic+0x174/0x468
> arm64_serror_panic+0x1b0/0x200
> do_serror+0x184/0x1e4
> el1_error+0x94/0x118
> el1_abort+0x40/0x68
> el1_sync_handler+0x58/0x88
> el1_sync+0x8c/0x140
> dwc3_readl+0x30/0x1a0
> dwc3_phy_setup+0x38/0x510
> dwc3_core_init+0x68/0xcd4
> dwc3_core_init_for_resume+0x10c/0x25c
> dwc3_resume_common+0x44/0x3d0
> dwc3_resume+0x5c/0xb8
> dpm_run_callback+0x70/0x488
> device_resume+0x250/0x2f8
> dpm_resume+0x258/0x9dc
>
> Signed-off-by: William Wu <william.wu@xxxxxxxxxxxxxx>
> ---
> Changes in v2:
> - Remove Change-Id.
>
> drivers/usb/dwc3/core.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 9c6bf054f15d..8274a44f2d6a 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -2185,9 +2185,11 @@ static int dwc3_resume(struct device *dev)
>
> pinctrl_pm_select_default_state(dev);
>
> - ret = dwc3_resume_common(dwc, PMSG_RESUME);
> - if (ret)
> - return ret;
> + if (!pm_runtime_suspended(dwc->dev)) {
> + ret = dwc3_resume_common(dwc, PMSG_RESUME);
> + if (ret)
> + return ret;
> + }
>
> pm_runtime_disable(dev);
> pm_runtime_set_active(dev);
> --
> 2.17.1
>
