Messages in this thread | | | Subject | Re: [PATCH] gpu: host1x: Free the IOMMU domain when there is no device to attach | From | Mikko Perttunen <> | Date | Tue, 11 Jul 2017 20:09:56 +0300 |
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On 07/11/2017 05:44 PM, Paul Kocialkowski wrote: > On Tue, 2017-07-11 at 14:37 +0000, Marcel Ziswiler wrote: >> On Tue, 2017-07-11 at 11:49 +0300, Paul Kocialkowski wrote: >>> On Mon, 2017-07-10 at 21:33 +0200, Paul Kocialkowski wrote: >>>> When there is no device to attach to the IOMMU domain, as may be >>>> the >>>> case when the device-tree does not contain the proper iommu node, >>>> it >>>> is >>>> best to keep going without IOMMU support rather than failing. >>>> This allows the driver to probe and function instead of taking >>>> down >>>> all of the tegra drm driver, leading to missing display support. >>> >>> Fixes: 404bfb78daf3 ("gpu: host1x: Add IOMMU support") >>> >>>> Signed-off-by: Paul Kocialkowski <contact-W9ppeneeCTY@public.gmane >>>> . >>>> org> >>>> --- >>>> drivers/gpu/host1x/dev.c | 8 +++++++- >>>> 1 file changed, 7 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c >>>> index ac65f52850a6..f296738d0de8 100644 >>>> --- a/drivers/gpu/host1x/dev.c >>>> +++ b/drivers/gpu/host1x/dev.c >>>> @@ -186,8 +186,13 @@ static int host1x_probe(struct >>>> platform_device >>>> *pdev) >>>> return -ENOMEM; >>>> >>>> err = iommu_attach_device(host->domain, &pdev- >>>>> dev); >>>> >>>> - if (err) >>>> + if (err == -ENODEV) { >>>> + iommu_domain_free(host->domain); >>>> + host->domain = NULL; >>>> + goto iommu_skip; >>>> + } else if (err) { >>>> goto fail_free_domain; >>>> + } >>>> >>>> geometry = &host->domain->geometry; >>>> >>>> @@ -198,6 +203,7 @@ static int host1x_probe(struct platform_device >>>> *pdev) >>>> host->iova_end = geometry->aperture_end; >>>> } >>>> >>>> +iommu_skip: >>>> err = host1x_channel_list_init(host); >>>> if (err) { >>>> dev_err(&pdev->dev, "failed to initialize channel >>>> list\n"); >> >> Please note that this does no longer cleanly apply after Mikko's 'gpu: >> host1x: Refactor channel allocation code' commit from June 15 already >> applied to current -next. Other than that > > Good to know! I intended this patch for fixing 4.12 stable, so I'm not > even entirely sure it should land in next. The patch that fixes the > device-tree to actually enable the iommu should be merged in priority. > > If that is the case and anyone wants this patch rebased to next, feel > free to let me know and I'll send a rebased version.
We should definitely have this for non-stable kernels too - it would be a bit strange if the driver worked if IOMMU support wasn't built into the kernel but failed if it was :) It can also be helpful for debugging to be able to disable IOMMU just for host1x.
> >> Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com> >> Tested-on: Apalis TK1, Apalis T30, Beaver, Colibri T30, Jetson-TK1 >> >> Finally graphics working again, thanks guys! > > Yay! :) >
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