Re: [PATCH v3] usb: dwc3: core: Prevent USB core invalid event buffer address access

[Thinh Nguyen]

On Thu, Aug 15, 2024, Selvarasu Ganesan wrote:
> This commit addresses an issue where the USB core could access an
> invalid event buffer address during runtime suspend, potentially causing
> SMMU faults and other memory issues in Exynos platforms. The problem
> arises from the following sequence.
>         1. In dwc3_gadget_suspend, there is a chance of a timeout when
>         moving the USB core to the halt state after clearing the
>         run/stop bit by software.
>         2. In dwc3_core_exit, the event buffer is cleared regardless of
>         the USB core's status, which may lead to an SMMU faults and
>         other memory issues. if the USB core tries to access the event
>         buffer address.
> 
> To prevent this hardware quirk on Exynos platforms, this commit ensures
> that the event buffer address is not cleared by software  when the USB
> core is active during runtime suspend by checking its status before
> clearing the buffer address.
> 
> Cc: stable@xxxxxxxxxxxxxxx # v6.1+

Usually there's no "v" to indicate version. I'm not sure if it'll be an
issue. Regardless,

Acked-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>

Thanks,
Thinh

> Signed-off-by: Selvarasu Ganesan <selvarasu.g@xxxxxxxxxxx>
> ---