On Tue, Jun 2, 2020 at 10:00 AM Andy Shevchenko <[email protected]> wrote: > > On Tue, Jun 2, 2020 at 4:38 PM Ruhl, Michael J <[email protected]> > wrote: > > >-----Original Message----- > > >From: dri-devel <[email protected]> On Behalf Of > > >Piotr Stankiewicz > > >Sent: Tuesday, June 2, 2020 5:21 AM > > >To: Alex Deucher <[email protected]>; Christian König > > ><[email protected]>; David Zhou <[email protected]>; David > > >Airlie <[email protected]>; Daniel Vetter <[email protected]> > > >Cc: Stankiewicz, Piotr <[email protected]>; dri- > > >[email protected]; [email protected]; linux- > > >[email protected] > > >Subject: [PATCH 07/15] drm/amdgpu: use PCI_IRQ_MSI_TYPES where > > >appropriate > > ... > > > > int nvec = pci_msix_vec_count(adev->pdev); > > > unsigned int flags; > > > > > >- if (nvec <= 0) { > > >+ if (nvec > 0) > > >+ flags = PCI_IRQ_MSI_TYPES; > > >+ else > > > flags = PCI_IRQ_MSI; > > >- } else { > > >- flags = PCI_IRQ_MSI | PCI_IRQ_MSIX; > > >- } > > > > Minor nit: > > > > Is it really necessary to set do this check? Can flags just > > be set? > > > > I.e.: > > flags = PCI_IRQ_MSI_TYPES; > > > > pci_alloc_irq_vector() tries stuff in order. If MSIX is not available, > > it will try MSI. > > That's also what I proposed earlier. But I suggested as well to wait > for AMD people to confirm that neither pci_msix_vec_count() nor flags > is needed and we can directly supply MSI_TYPES to the below call. >
I think it was leftover from debugging and just to be careful. We had some issues when we originally enabled MSI-X on certain boards. The fix was to just allocate a single vector (since that is all we use anyway) and we were using the wrong irq (pdev->irq vs pci_irq_vector(pdev, 0)). For reference, the original patch to add MSI-X: commit bd660f4f111161f60392dd02424c3a3d2240dc2f Author: shaoyunl <[email protected]> Date: Tue Oct 1 15:52:31 2019 -0400 drm/amdgpu : enable msix for amdgpu driver We might used out of the msi resources in some cloud project which have a lot gpu devices(including PF and VF), msix can provide enough resources from system level view Signed-off-by: shaoyunl <[email protected]> Reviewed-by: Alex Deucher <[email protected]> Signed-off-by: Alex Deucher <[email protected]> And the fix: commit 8a745c7ff2ddb8511ef760b4d9cb4cf56a15fc8d Author: Alex Deucher <[email protected]> Date: Thu Oct 3 10:34:30 2019 -0500 drm/amdgpu: improve MSI-X handling (v3) Check the number of supported vectors and fall back to MSI if we return or error or 0 MSI-X vectors. v2: only allocate one vector. We can't currently use more than one anyway. v3: install the irq on vector 0. Tested-by: Tom St Denis <[email protected]> Reviewed-by: Shaoyun liu <[email protected]> Signed-off-by: Alex Deucher <[email protected]> Alex _______________________________________________ amd-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/amd-gfx
