Messages in this thread | | | Date | Wed, 17 Nov 2021 15:07:51 +0200 | Subject | Re: [PATCH 2/8] bus: fsl-mc: handle DMA config deferral in ACPI case | From | Laurentiu Tudor <> |
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On 11/12/2021 7:31 PM, Daniel Thompson wrote: > On Thu, Nov 11, 2021 at 06:36:58PM +0100, Jon Nettleton wrote: >> On Thu, Nov 11, 2021 at 6:23 PM Daniel Thompson >> <daniel.thompson@linaro.org> wrote: >>> >>> Hi Laurentiu >>> >>> On Thu, Jul 15, 2021 at 05:07:12PM +0300, laurentiu.tudor@nxp.com wrote: >>>> From: Laurentiu Tudor <laurentiu.tudor@nxp.com> >>>> >>>> ACPI DMA configure API may return a defer status code, so handle it. >>>> On top of this, move the MC firmware resume after the DMA setup >>>> is completed to avoid crashing due to DMA setup not being done yet or >>>> being deferred. >>>> >>>> Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com> >>> >>> I saw regressions on my Honeycomb LX2 (NXP LX2060A) when I switched to >>> v5.15. It seems like it results in so many sMMU errors that the system >>> cannot function correctly (it's only about a 75% chance the system will >>> boot to GUI and even if it does boot successfully the system will hang >>> up soon after). >>> >>> Bisect took me up a couple of blind alleys (mostly due to unrelated boot >>> problems in v5.14-rc2) by eventually led me to this patch as the cause. >>> Applying/unapplying this patch to a v5.14-rc3 tree will provoke/fix the >>> problem and reverting it against v5.15 also resolves the problem. >>> >>> Is there some specific firmware version required for this patch to work >>> correctly? >> >> This patch was merged as a requirement for operational on board networking. >> This was merged as a prerequisite to landing the patches to support MDIO and >> phy initialization in general. > > Interesting. > > I assumed the change of behaviour comes from properly handling > -EPROBE_DEFER (which can hardly be regarded as a fault with the patch). > > Having said that the patch does not seem to be mandatory to get the 1G > networking working on Honeycomb LX2 (running ACPI). By taking v5.15 and > reverting as I shared previously, I am still able to access the network > using the 1G port on the back of the unit (although I didn't do any > performance tests). > > >> The correct solution for the problem you are seeing is the ACPI >> maintainers figuring out how to land the IORT RMR patchset. Until >> that is done the only workaround is setting "arm-smmu.disable_bypass=0 >> iommu.passthrough=1" on the kernel commandline. The latter option is >> required since 5.15 and I haven't had time or energy to figure out >> why. The proper solution is to just land the IORT RMR patchset and >> let HoneyComb run with the SMMU enabled. > > Thanks for the update. I'll probably adopt iommu.passthrough=1 for now. > That allows me to adopt a distro kernel when it updates to v5.15.
The "iommu.passthrough=1" kernel arg shouldn't be needed. By chance, do you remember what errors were you seeing? What was failing?
--- Thanks & Best Regards, Laurentiu
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