Re: [PATCH] drm/amd: Fix the flag setting code for interrupt request

[Christian König]

Am 04.09.23 um 08:05 schrieb Ma Jun:
[1] Remove the irq flags setting code since pci_alloc_irq_vectors()
handles these flags.
[2] Free the msi vectors in case of error.
Signed-off-by: Ma Jun <jun....@amd.com>
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c | 43 ++++++++++++++-----------
  1 file changed, 25 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
index fa6d0adcec20..17043a1e37a5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
@@ -271,28 +271,28 @@ static void amdgpu_restore_msix(struct amdgpu_device 
*adev)
  int amdgpu_irq_init(struct amdgpu_device *adev)
  {
        int r = 0;

While at it please remove the assignment here.

Unless really necessary initializing local variables is rather frowned upon.

Apart from that Alex needs to take a look at this, I'm not that familiar 
with this code.

Christian.

-       unsigned int irq;
+       unsigned int irq, flags;
  
  	spin_lock_init(&adev->irq.lock);
  
  	/* Enable MSI if not disabled by module parameter */
        adev->irq.msi_enabled = false;
  
+	if (amdgpu_msi_ok(adev))
+               flags = PCI_IRQ_MSI | PCI_IRQ_MSIX;
+       else
+               flags = PCI_IRQ_LEGACY;
+
+       /* we only need one vector */
+       r = pci_alloc_irq_vectors(adev->pdev, 1, 1, flags);
+       if (r < 0) {
+               dev_err(adev->dev, "Failed to alloc msi vectors\n");
+               return r;
+       }
+
        if (amdgpu_msi_ok(adev)) {
-               int nvec = pci_msix_vec_count(adev->pdev);
-               unsigned int flags;
-
-               if (nvec <= 0)
-                       flags = PCI_IRQ_MSI;
-               else
-                       flags = PCI_IRQ_MSI | PCI_IRQ_MSIX;
-
-               /* we only need one vector */
-               nvec = pci_alloc_irq_vectors(adev->pdev, 1, 1, flags);
-               if (nvec > 0) {
-                       adev->irq.msi_enabled = true;
-                       dev_dbg(adev->dev, "using MSI/MSI-X.\n");
-               }
+               adev->irq.msi_enabled = true;
+               dev_dbg(adev->dev, "using MSI/MSI-X.\n");
        }
  
  	INIT_WORK(&adev->irq.ih1_work, amdgpu_irq_handle_ih1);
@@ -302,22 +302,29 @@ int amdgpu_irq_init(struct amdgpu_device *adev)
        /* Use vector 0 for MSI-X. */
        r = pci_irq_vector(adev->pdev, 0);
        if (r < 0)
-               return r;
+               goto free_vectors;
        irq = r;
  
  	/* PCI devices require shared interrupts. */
        r = request_irq(irq, amdgpu_irq_handler, IRQF_SHARED, 
adev_to_drm(adev)->driver->name,
                        adev_to_drm(adev));
        if (r)
-               return r;
+               goto free_vectors;
+
        adev->irq.installed = true;
        adev->irq.irq = irq;
        adev_to_drm(adev)->max_vblank_count = 0x00ffffff;
  
  	DRM_DEBUG("amdgpu: irq initialized.\n");
        return 0;
-}
  
+free_vectors:
+       if (adev->irq.msi_enabled)
+               pci_free_irq_vectors(adev->pdev);
+
+       adev->irq.msi_enabled = false;
+       return r;
+}
  
  void amdgpu_irq_fini_hw(struct amdgpu_device *adev)
  {