On Sat, Aug 17, 2024 at 07:13:53PM +0530, Selvarasu Ganesan wrote: > > On 8/17/2024 10:47 AM, Greg KH wrote: > > On Fri, Aug 16, 2024 at 09:13:09PM +0530, Selvarasu Ganesan wrote: > >> On 8/16/2024 3:25 PM, Greg KH wrote: > >>> On Thu, Aug 15, 2024 at 12:18:31PM +0530, 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+ > >>> Any hint as to what commit id this fixes? > >>> > >>> thanks, > >>> > >>> greg k-h > >> > >> Hi Greg, > >> > >> This issue is not related to any particular commit. The given fix is > >> address a hardware quirk on the Exynos platform. And we require it to be > >> backported on stable kernel 6.1 and above all stable kernel. > > If it's a hardware quirk issue, why are you restricting it to a specific > > kernel release and not a specific kernel commit? Why not 5.15? 5.4? > > Hi Greg, > > I mentioned a specific kernel because our platform is set to be tested > and functioning with kernels 6.1 and above, and the issue was reported > with these kernel versions. However, we would be fine if all stable > kernels, such as 5.4 and 5.15, were backported. In this case, if you > need a new patch version to update the Cc tag for all stable kernels, > please suggest the Cc tag to avoid confusion in next version. I'll fix it up when applying it, thanks. greg k-h
