Re: [PATCH 01/14] drm/amdgpu: Convert to Linux IRQ interfaces

[Alex Deucher <alexdeucher@gmail.com>]

On Wed, Jul 28, 2021 at 6:27 AM Christian König
<christian.koenig@amd.com> wrote:
>
> Am 27.07.21 um 20:27 schrieb Thomas Zimmermann:
> > Drop the DRM IRQ midlayer in favor of Linux IRQ interfaces. DRM's
> > IRQ helpers are mostly useful for UMS drivers. Modern KMS drivers
> > don't benefit from using it.
> >
> > DRM IRQ callbacks are now being called directly or inlined.
> >
> > The interrupt number returned by pci_msi_vector() is now stored
> > in struct amdgpu_irq. Calls to pci_msi_vector() can fail and return
> > a negative errno code. Abort initlaizaton in thi case. The DRM IRQ
> > midlayer does not handle this correctly.
> >
> > Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
>
> Alex needs to take a look at this as well, but of hand the patch is
> Acked-by: Christian König <christian.koenig@amd.com>.

Looks good to me as well:
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

>
> Thanks,
> Christian.
>
> > ---
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c |  1 -
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c | 21 ++++++++++++++-------
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h |  2 +-
> >   3 files changed, 15 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > index 2bd13fc2541a..1e05b5aa94e7 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > @@ -1775,7 +1775,6 @@ static const struct drm_driver amdgpu_kms_driver = {
> >       .open = amdgpu_driver_open_kms,
> >       .postclose = amdgpu_driver_postclose_kms,
> >       .lastclose = amdgpu_driver_lastclose_kms,
> > -     .irq_handler = amdgpu_irq_handler,
> >       .ioctls = amdgpu_ioctls_kms,
> >       .num_ioctls = ARRAY_SIZE(amdgpu_ioctls_kms),
> >       .dumb_create = amdgpu_mode_dumb_create,
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> > index 0d01cfaca77e..a36cdc7323f4 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
> > @@ -46,7 +46,6 @@
> >   #include <linux/pci.h>
> >
> >   #include <drm/drm_crtc_helper.h>
> > -#include <drm/drm_irq.h>
> >   #include <drm/drm_vblank.h>
> >   #include <drm/amdgpu_drm.h>
> >   #include <drm/drm_drv.h>
> > @@ -184,7 +183,7 @@ void amdgpu_irq_disable_all(struct amdgpu_device *adev)
> >    * Returns:
> >    * result of handling the IRQ, as defined by &irqreturn_t
> >    */
> > -irqreturn_t amdgpu_irq_handler(int irq, void *arg)
> > +static irqreturn_t amdgpu_irq_handler(int irq, void *arg)
> >   {
> >       struct drm_device *dev = (struct drm_device *) arg;
> >       struct amdgpu_device *adev = drm_to_adev(dev);
> > @@ -307,6 +306,7 @@ static void amdgpu_restore_msix(struct amdgpu_device *adev)
> >   int amdgpu_irq_init(struct amdgpu_device *adev)
> >   {
> >       int r = 0;
> > +     unsigned int irq;
> >
> >       spin_lock_init(&adev->irq.lock);
> >
> > @@ -349,15 +349,22 @@ int amdgpu_irq_init(struct amdgpu_device *adev)
> >       INIT_WORK(&adev->irq.ih2_work, amdgpu_irq_handle_ih2);
> >       INIT_WORK(&adev->irq.ih_soft_work, amdgpu_irq_handle_ih_soft);
> >
> > -     adev->irq.installed = true;
> > -     /* Use vector 0 for MSI-X */
> > -     r = drm_irq_install(adev_to_drm(adev), pci_irq_vector(adev->pdev, 0));
> > +     /* Use vector 0 for MSI-X. */
> > +     r = pci_irq_vector(adev->pdev, 0);
> > +     if (r < 0)
> > +             return r;
> > +     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) {
> > -             adev->irq.installed = false;
> >               if (!amdgpu_device_has_dc_support(adev))
> >                       flush_work(&adev->hotplug_work);
> >               return r;
> >       }
> > +     adev->irq.installed = true;
> > +     adev->irq.irq = irq;
> >       adev_to_drm(adev)->max_vblank_count = 0x00ffffff;
> >
> >       DRM_DEBUG("amdgpu: irq initialized.\n");
> > @@ -368,7 +375,7 @@ int amdgpu_irq_init(struct amdgpu_device *adev)
> >   void amdgpu_irq_fini_hw(struct amdgpu_device *adev)
> >   {
> >       if (adev->irq.installed) {
> > -             drm_irq_uninstall(&adev->ddev);
> > +             free_irq(adev->irq.irq, adev_to_drm(adev));
> >               adev->irq.installed = false;
> >               if (adev->irq.msi_enabled)
> >                       pci_free_irq_vectors(adev->pdev);
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h
> > index 78ad4784cc74..e9f2c11ea416 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h
> > @@ -80,6 +80,7 @@ struct amdgpu_irq_src_funcs {
> >
> >   struct amdgpu_irq {
> >       bool                            installed;
> > +     unsigned int                    irq;
> >       spinlock_t                      lock;
> >       /* interrupt sources */
> >       struct amdgpu_irq_client        client[AMDGPU_IRQ_CLIENTID_MAX];
> > @@ -100,7 +101,6 @@ struct amdgpu_irq {
> >   };
> >
> >   void amdgpu_irq_disable_all(struct amdgpu_device *adev);
> > -irqreturn_t amdgpu_irq_handler(int irq, void *arg);
> >
> >   int amdgpu_irq_init(struct amdgpu_device *adev);
> >   void amdgpu_irq_fini_sw(struct amdgpu_device *adev);
>