Re: [PATCH v1] usb: dwc3: core: Add shutdown callback for dwc3

[Sergei Shtylyov <sergei.shtylyov@gmail.com>]

Hello!

On 23.03.2021 22:27, Sandeep Maheswaram wrote:

> This patch adds a shutdown callback to USB DWC core driver to ensure that
> it is properly shutdown in reboot/shutdown path. This is required
> where SMMU address translation is enabled like on SC7180
> SoC and few others. If the hardware is still accessing memory after
> SMMU translation is disabled as part of SMMU shutdown callback in
> system reboot or shutdown path, then IOVAs(I/O virtual address)

   Space before (, please.

> which it was using will go on the bus as the physical addresses which
> might result in unknown crashes (NoC/interconnect errors).
> 
> Previously this was added in dwc3 qcom glue driver.
> https://patchwork.kernel.org/project/linux-arm-msm/list/?series=382449
> But observed kernel panic as glue driver shutdown getting called after
> iommu shutdown. As we are adding iommu nodes in dwc core node
> in device tree adding shutdown callback in core driver seems correct.
> 
> Signed-off-by: Sandeep Maheswaram <sanm@codeaurora.org>
> ---
>   drivers/usb/dwc3/core.c | 26 +++++++++++++++++++-------
>   1 file changed, 19 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 94fdbe5..777b2b5 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
[...]
> @@ -1976,6 +1987,7 @@ MODULE_DEVICE_TABLE(acpi, dwc3_acpi_match);
>   static struct platform_driver dwc3_driver = {
>   	.probe		= dwc3_probe,
>   	.remove		= dwc3_remove,
> +	.shutdown   = dwc3_shutdown,

    Please indent = with tabs as above and below.

>   	.driver		= {
>   		.name	= "dwc3",
>   		.of_match_table	= of_match_ptr(of_dwc3_match),

MBR, Sergei