Messages in this thread | | | Date | Tue, 30 Mar 2021 18:18:43 +0530 | From | Sai Prakash Ranjan <> | Subject | Re: [PATCH v1] usb: dwc3: core: Add shutdown callback for dwc3 |
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On 2021-03-30 16:46, Greg Kroah-Hartman wrote: > 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...
You are replying now to the same patch which adds this shutdown callback :) Anyways the qcom dwc3 driver patch which is abandoned which is also mentioned in the commit text is here [1] and the new shutdown callback patch which we are both replying to is in here [2]
[1] https://lore.kernel.org/lkml/1605162619-10064-1-git-send-email-sanm@codeaurora.org/
[2] https://lore.kernel.org/lkml/1616527652-7937-1-git-send-email-sanm@codeaurora.org/
Thanks, Sai
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