Messages in this thread | | | Subject | Re: [PATCH v1] usb: dwc3: core: Add shutdown callback for dwc3 | From | Sandeep Maheswaram <> | Date | Thu, 8 Apr 2021 10:22:57 +0530 |
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On 3/30/2021 7:02 PM, Greg Kroah-Hartman wrote: > On Tue, Mar 30, 2021 at 06:18:43PM +0530, Sai Prakash Ranjan wrote: >> 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, so, what am I supposed to do here? The patch is long gone from > my queue... > > greg k-h
Hi Greg,
Should I resend this patch ? If so let me know your about opinion about Stephen's comment on just calling dwc3_remove in
dwc3_shutdown and ignoring return value.
https://lore.kernel.org/patchwork/patch/1401242/#1599316
Thanks
Sandeep
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