On Tue, Jun 2, 2020 at 10:00 AM Andy Shevchenko andy.shevchenko@gmail.com wrote:
On Tue, Jun 2, 2020 at 4:38 PM Ruhl, Michael J michael.j.ruhl@intel.com wrote:
-----Original Message----- From: dri-devel dri-devel-bounces@lists.freedesktop.org On Behalf Of Piotr Stankiewicz Sent: Tuesday, June 2, 2020 5:21 AM To: Alex Deucher alexander.deucher@amd.com; Christian König christian.koenig@amd.com; David Zhou David1.Zhou@amd.com; David Airlie airlied@linux.ie; Daniel Vetter daniel@ffwll.ch Cc: Stankiewicz, Piotr piotr.stankiewicz@intel.com; dri- devel@lists.freedesktop.org; amd-gfx@lists.freedesktop.org; linux- kernel@vger.kernel.org Subject: [PATCH 07/15] drm/amdgpu: use PCI_IRQ_MSI_TYPES where appropriate
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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 shaoyun.liu@amd.com 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 shaoyun.liu@amd.com Reviewed-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com
And the fix:
commit 8a745c7ff2ddb8511ef760b4d9cb4cf56a15fc8d Author: Alex Deucher alexander.deucher@amd.com 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 tom.stdenis@amd.com Reviewed-by: Shaoyun liu shaoyun.liu@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com
Alex