On Tue, Mar 30, 2021 at 03:25:58PM +0530, Sai Prakash Ranjan wrote: > On 2021-03-30 14:37, Greg Kroah-Hartman wrote: > > On Tue, Mar 30, 2021 at 02:12:04PM +0530, Sandeep Maheswaram wrote: > > > > > > On 3/26/2021 7:07 PM, Greg Kroah-Hartman wrote: > > > > On Wed, Mar 24, 2021 at 12:57:32AM +0530, 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) > > > > > 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. > > > > So shouldn't you also remove this from the qcom glue driver at the same > > > > time? Please submit both as a patch series. > > > > > > > > thanks, > > > > > > > > greg k-h > > > > > > Hi Greg, > > > > > > The qcom glue driver patch is not merged yet. I have just mentioned > > > for it for reference. > > > > You know that we can not add callbacks for no in-kernel user, so what > > good is this patch for now? > > > > What in-kernel user? Since when does shutdown callback need an in-kernel > user? When you reboot or shutdown a system, it gets called. The reason > why the shutdown callback is needed is provided in the commit text. As I can't see the patch here, I have no idea...
