[PATCH v8 6/6] drm/{i915,xe}: Implement fbdev emulation as in-kernel client

Hogander, Jouni jouni.hogander at intel.com
Tue Apr 23 11:36:14 UTC 2024


On Tue, 2024-04-23 at 13:13 +0200, Thomas Zimmermann wrote:
> Hi
> 
> Am 22.04.24 um 16:11 schrieb Hogander, Jouni:
> > On Tue, 2024-04-09 at 10:04 +0200, Thomas Zimmermann wrote:
> > > Replace all code that initializes or releases fbdev emulation
> > > throughout the driver. Instead initialize the fbdev client by a
> > > single call to intel_fbdev_setup() after i915 has registered its
> > > DRM device. Just like similar code in other drivers, i915 fbdev
> > > emulation now acts like a regular DRM client. Do the same for xe.
> > > 
> > > The fbdev client setup consists of the initial preparation and
> > > the
> > > hot-plugging of the display. The latter creates the fbdev device
> > > and sets up the fbdev framebuffer. The setup performs display
> > > hot-plugging once. If no display can be detected, DRM probe
> > > helpers
> > > re-run the detection on each hotplug event.
> > > 
> > > A call to drm_client_dev_unregister() releases all in-kernel
> > > clients
> > > automatically. No further action is required within i915. If the
> > > fbdev
> > > framebuffer has been fully set up, struct fb_ops.fb_destroy
> > > implements
> > > the release. For partially initialized emulation, the fbdev
> > > client
> > > reverts the initial setup. Do the same for xe and remove its call
> > > to
> > > intel_fbdev_fini().
> > > 
> > > v8:
> > > - setup client in intel_display_driver_register (Jouni)
> > > - mention xe in commit message
> > > 
> > > v7:
> > > - update xe driver
> > > - reword commit message
> > > 
> > > v6:
> > > - use 'i915' for i915 device (Jouni)
> > > - remove unnecessary code for non-atomic mode setting (Jouni,
> > > Ville)
> > > - fix function name in commit message (Jouni)
> > > 
> > > v3:
> > > -  as before, silently ignore devices without displays
> > > 
> > > v2:
> > > -  let drm_client_register() handle initial hotplug
> > > -  fix driver name in error message (Jani)
> > > -  fix non-fbdev build (kernel test robot)
> > > 
> > > Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> > Reviewed-by: Jouni Högander <jouni.hogander at intel.com>
> 
> Thank you so much. All patches has R-bs. Can you add the series to
> the 
> intel tree?

Is it ok to merge patch 01/06 via intel tree as well?

Rodrigo, This set is containing Xe display changes as well. Is it ok to
push this via drm-intel?

BR,

Jouni Högander

> 
> Best regards
> Thomas
> 
> > 
> > > ---
> > >   drivers/gpu/drm/i915/display/intel_display.c  |   1 -
> > >   .../drm/i915/display/intel_display_driver.c   |  20 +-
> > >   drivers/gpu/drm/i915/display/intel_fbdev.c    | 177 ++++++++---
> > > -----
> > > --
> > >   drivers/gpu/drm/i915/display/intel_fbdev.h    |  20 +-
> > >   drivers/gpu/drm/xe/display/xe_display.c       |   2 -
> > >   5 files changed, 80 insertions(+), 140 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > > b/drivers/gpu/drm/i915/display/intel_display.c
> > > index 614e60420a29a..161a5aabf6746 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > > @@ -85,7 +85,6 @@
> > >   #include "intel_dvo.h"
> > >   #include "intel_fb.h"
> > >   #include "intel_fbc.h"
> > > -#include "intel_fbdev.h"
> > >   #include "intel_fdi.h"
> > >   #include "intel_fifo_underrun.h"
> > >   #include "intel_frontbuffer.h"
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display_driver.c
> > > b/drivers/gpu/drm/i915/display/intel_display_driver.c
> > > index e5f052d4ff1cc..ed8589fa35448 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display_driver.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_display_driver.c
> > > @@ -514,10 +514,6 @@ int intel_display_driver_probe(struct
> > > drm_i915_private *i915)
> > >   
> > >          intel_overlay_setup(i915);
> > >   
> > > -       ret = intel_fbdev_init(&i915->drm);
> > > -       if (ret)
> > > -               return ret;
> > > -
> > >          /* Only enable hotplug handling once the fbdev is fully
> > > set
> > > up. */
> > >          intel_hpd_init(i915);
> > >   
> > > @@ -544,16 +540,6 @@ void intel_display_driver_register(struct
> > > drm_i915_private *i915)
> > >   
> > >          intel_display_debugfs_register(i915);
> > >   
> > > -       /*
> > > -        * Some ports require correctly set-up hpd registers for
> > > -        * detection to work properly (leading to ghost connected
> > > -        * connector status), e.g. VGA on gm45.  Hence we can
> > > only
> > > set
> > > -        * up the initial fbdev config after hpd irqs are fully
> > > -        * enabled. We do it last so that the async config cannot
> > > run
> > > -        * before the connectors are registered.
> > > -        */
> > > -       intel_fbdev_initial_config_async(i915);
> > > -
> > >          /*
> > >           * We need to coordinate the hotplugs with the
> > > asynchronous
> > >           * fbdev configuration, for which we use the
> > > @@ -562,6 +548,8 @@ void intel_display_driver_register(struct
> > > drm_i915_private *i915)
> > >          drm_kms_helper_poll_init(&i915->drm);
> > >          intel_hpd_poll_disable(i915);
> > >   
> > > +       intel_fbdev_setup(i915);
> > > +
> > >          intel_display_device_info_print(DISPLAY_INFO(i915),
> > >                                          DISPLAY_RUNTIME_INFO(i91
> > > 5),
> > > &p);
> > >   }
> > > @@ -597,9 +585,6 @@ void intel_display_driver_remove_noirq(struct
> > > drm_i915_private *i915)
> > >           */
> > >          intel_hpd_poll_fini(i915);
> > >   
> > > -       /* poll work can call into fbdev, hence clean that up
> > > afterwards */
> > > -       intel_fbdev_fini(i915);
> > > -
> > >          intel_unregister_dsm_handler();
> > >   
> > >          /* flush any delayed tasks or pending work */
> > > @@ -640,7 +625,6 @@ void intel_display_driver_unregister(struct
> > > drm_i915_private *i915)
> > >   
> > >          drm_client_dev_unregister(&i915->drm);
> > >   
> > > -       intel_fbdev_unregister(i915);
> > >          /*
> > >           * After flushing the fbdev (incl. a late async config
> > > which
> > >           * will have delayed queuing of a hotplug event), then
> > > flush
> > > diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c
> > > b/drivers/gpu/drm/i915/display/intel_fbdev.c
> > > index f783de611a7f5..bda702c2cab8e 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_fbdev.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_fbdev.c
> > > @@ -24,7 +24,6 @@
> > >    *     David Airlie
> > >    */
> > >   
> > > -#include <linux/async.h>
> > >   #include <linux/console.h>
> > >   #include <linux/delay.h>
> > >   #include <linux/errno.h>
> > > @@ -39,6 +38,7 @@
> > >   #include <linux/vga_switcheroo.h>
> > >   
> > >   #include <drm/drm_crtc.h>
> > > +#include <drm/drm_crtc_helper.h>
> > >   #include <drm/drm_fb_helper.h>
> > >   #include <drm/drm_fourcc.h>
> > >   #include <drm/drm_gem_framebuffer_helper.h>
> > > @@ -58,7 +58,6 @@ struct intel_fbdev {
> > >          struct intel_framebuffer *fb;
> > >          struct i915_vma *vma;
> > >          unsigned long vma_flags;
> > > -       async_cookie_t cookie;
> > >          int preferred_bpp;
> > >   
> > >          /* Whether or not fbdev hpd processing is temporarily
> > > suspended */
> > > @@ -135,6 +134,26 @@ static int intel_fbdev_mmap(struct fb_info
> > > *info, struct vm_area_struct *vma)
> > >          return i915_gem_fb_mmap(obj, vma);
> > >   }
> > >   
> > > +static void intel_fbdev_fb_destroy(struct fb_info *info)
> > > +{
> > > +       struct drm_fb_helper *fb_helper = info->par;
> > > +       struct intel_fbdev *ifbdev = container_of(fb_helper,
> > > struct
> > > intel_fbdev, helper);
> > > +
> > > +       drm_fb_helper_fini(&ifbdev->helper);
> > > +
> > > +       /*
> > > +        * We rely on the object-free to release the VMA pinning
> > > for
> > > +        * the info->screen_base mmaping. Leaking the VMA is
> > > simpler
> > > than
> > > +        * trying to rectify all the possible error paths leading
> > > here.
> > > +        */
> > > +       intel_unpin_fb_vma(ifbdev->vma, ifbdev->vma_flags);
> > > +       drm_framebuffer_remove(&ifbdev->fb->base);
> > > +
> > > +       drm_client_release(&fb_helper->client);
> > > +       drm_fb_helper_unprepare(&ifbdev->helper);
> > > +       kfree(ifbdev);
> > > +}
> > > +
> > >   __diag_push();
> > >   __diag_ignore_all("-Woverride-init", "Allow field
> > > initialization
> > > overrides for fb ops");
> > >   
> > > @@ -147,6 +166,7 @@ static const struct fb_ops intelfb_ops = {
> > >          .fb_pan_display = intel_fbdev_pan_display,
> > >          __FB_DEFAULT_DEFERRED_OPS_DRAW(intel_fbdev),
> > >          .fb_mmap = intel_fbdev_mmap,
> > > +       .fb_destroy = intel_fbdev_fb_destroy,
> > >   };
> > >   
> > >   __diag_pop();
> > > @@ -158,7 +178,6 @@ static int intelfb_create(struct
> > > drm_fb_helper
> > > *helper,
> > >          struct intel_framebuffer *intel_fb = ifbdev->fb;
> > >          struct drm_device *dev = helper->dev;
> > >          struct drm_i915_private *dev_priv = to_i915(dev);
> > > -       struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
> > >          const struct i915_gtt_view view = {
> > >                  .type = I915_GTT_VIEW_NORMAL,
> > >          };
> > > @@ -250,7 +269,7 @@ static int intelfb_create(struct
> > > drm_fb_helper
> > > *helper,
> > >          ifbdev->vma_flags = flags;
> > >   
> > >          intel_runtime_pm_put(&dev_priv->runtime_pm, wakeref);
> > > -       vga_switcheroo_client_fb_set(pdev, info);
> > > +
> > >          return 0;
> > >   
> > >   out_unpin:
> > > @@ -276,26 +295,6 @@ static const struct drm_fb_helper_funcs
> > > intel_fb_helper_funcs = {
> > >          .fb_dirty = intelfb_dirty,
> > >   };
> > >   
> > > -static void intel_fbdev_destroy(struct intel_fbdev *ifbdev)
> > > -{
> > > -       /* We rely on the object-free to release the VMA pinning
> > > for
> > > -        * the info->screen_base mmaping. Leaking the VMA is
> > > simpler
> > > than
> > > -        * trying to rectify all the possible error paths leading
> > > here.
> > > -        */
> > > -
> > > -       drm_fb_helper_fini(&ifbdev->helper);
> > > -
> > > -       if (ifbdev->vma)
> > > -               intel_unpin_fb_vma(ifbdev->vma, ifbdev-
> > > >vma_flags);
> > > -
> > > -       if (ifbdev->fb)
> > > -               drm_framebuffer_remove(&ifbdev->fb->base);
> > > -
> > > -       drm_client_release(&ifbdev->helper.client);
> > > -       drm_fb_helper_unprepare(&ifbdev->helper);
> > > -       kfree(ifbdev);
> > > -}
> > > -
> > >   /*
> > >    * Build an intel_fbdev struct using a BIOS allocated
> > > framebuffer,
> > > if possible.
> > >    * The core display code will have read out the current plane
> > > configuration,
> > > @@ -459,16 +458,6 @@ static void
> > > intel_fbdev_suspend_worker(struct
> > > work_struct *work)
> > >                                  true);
> > >   }
> > >   
> > > -static void intel_fbdev_sync(struct intel_fbdev *ifbdev)
> > > -{
> > > -       if (!ifbdev->cookie)
> > > -               return;
> > > -
> > > -       /* Only serialises with all preceding async calls, hence
> > > +1
> > > */
> > > -       async_synchronize_cookie(ifbdev->cookie + 1);
> > > -       ifbdev->cookie = 0;
> > > -}
> > > -
> > >   /* Suspends/resumes fbdev processing of incoming HPD events.
> > > When
> > > resuming HPD
> > >    * processing, fbdev will perform a full connector reprobe if a
> > > hotplug event
> > >    * was received while HPD was suspended.
> > > @@ -559,8 +548,6 @@ static int
> > > intel_fbdev_output_poll_changed(struct
> > > drm_device *dev)
> > >          if (!ifbdev)
> > >                  return -EINVAL;
> > >   
> > > -       intel_fbdev_sync(ifbdev);
> > > -
> > >          mutex_lock(&ifbdev->hpd_lock);
> > >          send_hpd = !ifbdev->hpd_suspended;
> > >          ifbdev->hpd_waiting = true;
> > > @@ -580,7 +567,6 @@ static int intel_fbdev_restore_mode(struct
> > > drm_i915_private *dev_priv)
> > >          if (!ifbdev)
> > >                  return -EINVAL;
> > >   
> > > -       intel_fbdev_sync(ifbdev);
> > >          if (!ifbdev->vma)
> > >                  return -ENOMEM;
> > >   
> > > @@ -598,7 +584,20 @@ static int intel_fbdev_restore_mode(struct
> > > drm_i915_private *dev_priv)
> > >    */
> > >   
> > >   static void intel_fbdev_client_unregister(struct drm_client_dev
> > > *client)
> > > -{ }
> > > +{
> > > +       struct drm_fb_helper *fb_helper =
> > > drm_fb_helper_from_client(client);
> > > +       struct drm_device *dev = fb_helper->dev;
> > > +       struct pci_dev *pdev = to_pci_dev(dev->dev);
> > > +
> > > +       if (fb_helper->info) {
> > > +               vga_switcheroo_client_fb_set(pdev, NULL);
> > > +               drm_fb_helper_unregister_info(fb_helper);
> > > +       } else {
> > > +               drm_fb_helper_unprepare(fb_helper);
> > > +               drm_client_release(&fb_helper->client);
> > > +               kfree(fb_helper);
> > > +       }
> > > +}
> > >   
> > >   static int intel_fbdev_client_restore(struct drm_client_dev
> > > *client)
> > >   {
> > > @@ -616,7 +615,31 @@ static int intel_fbdev_client_restore(struct
> > > drm_client_dev *client)
> > >   
> > >   static int intel_fbdev_client_hotplug(struct drm_client_dev
> > > *client)
> > >   {
> > > -       return intel_fbdev_output_poll_changed(client->dev);
> > > +       struct drm_fb_helper *fb_helper =
> > > drm_fb_helper_from_client(client);
> > > +       struct drm_device *dev = client->dev;
> > > +       struct pci_dev *pdev = to_pci_dev(dev->dev);
> > > +       int ret;
> > > +
> > > +       if (dev->fb_helper)
> > > +               return intel_fbdev_output_poll_changed(dev);
> > > +
> > > +       ret = drm_fb_helper_init(dev, fb_helper);
> > > +       if (ret)
> > > +               goto err_drm_err;
> > > +
> > > +       ret = drm_fb_helper_initial_config(fb_helper);
> > > +       if (ret)
> > > +               goto err_drm_fb_helper_fini;
> > > +
> > > +       vga_switcheroo_client_fb_set(pdev, fb_helper->info);
> > > +
> > > +       return 0;
> > > +
> > > +err_drm_fb_helper_fini:
> > > +       drm_fb_helper_fini(fb_helper);
> > > +err_drm_err:
> > > +       drm_err(dev, "Failed to setup i915 fbdev emulation
> > > (ret=%d)\n", ret);
> > > +       return ret;
> > >   }
> > >   
> > >   static const struct drm_client_funcs intel_fbdev_client_funcs =
> > > {
> > > @@ -626,22 +649,23 @@ static const struct drm_client_funcs
> > > intel_fbdev_client_funcs = {
> > >          .hotplug        = intel_fbdev_client_hotplug,
> > >   };
> > >   
> > > -int intel_fbdev_init(struct drm_device *dev)
> > > +void intel_fbdev_setup(struct drm_i915_private *i915)
> > >   {
> > > -       struct drm_i915_private *dev_priv = to_i915(dev);
> > > +       struct drm_device *dev = &i915->drm;
> > >          struct intel_fbdev *ifbdev;
> > >          int ret;
> > >   
> > > -       if (drm_WARN_ON(dev, !HAS_DISPLAY(dev_priv)))
> > > -               return -ENODEV;
> > > +       if (!HAS_DISPLAY(i915))
> > > +               return;
> > >   
> > >          ifbdev = kzalloc(sizeof(*ifbdev), GFP_KERNEL);
> > >          if (!ifbdev)
> > > -               return -ENOMEM;
> > > -
> > > -       mutex_init(&ifbdev->hpd_lock);
> > > +               return;
> > >          drm_fb_helper_prepare(dev, &ifbdev->helper, 32,
> > > &intel_fb_helper_funcs);
> > >   
> > > +       i915->display.fbdev.fbdev = ifbdev;
> > > +       INIT_WORK(&i915->display.fbdev.suspend_work,
> > > intel_fbdev_suspend_worker);
> > > +       mutex_init(&ifbdev->hpd_lock);
> > >          if (intel_fbdev_init_bios(dev, ifbdev))
> > >                  ifbdev->helper.preferred_bpp = ifbdev-
> > > >preferred_bpp;
> > >          else
> > > @@ -649,68 +673,19 @@ int intel_fbdev_init(struct drm_device
> > > *dev)
> > >   
> > >          ret = drm_client_init(dev, &ifbdev->helper.client,
> > > "intel-
> > > fbdev",
> > >                                &intel_fbdev_client_funcs);
> > > -       if (ret)
> > > +       if (ret) {
> > > +               drm_err(dev, "Failed to register client: %d\n",
> > > ret);
> > >                  goto err_drm_fb_helper_unprepare;
> > > +       }
> > >   
> > > -       ret = drm_fb_helper_init(dev, &ifbdev->helper);
> > > -       if (ret)
> > > -               goto err_drm_client_release;
> > > -
> > > -       dev_priv->display.fbdev.fbdev = ifbdev;
> > > -       INIT_WORK(&dev_priv->display.fbdev.suspend_work,
> > > intel_fbdev_suspend_worker);
> > > +       drm_client_register(&ifbdev->helper.client);
> > >   
> > > -       return 0;
> > > +       return;
> > >   
> > > -err_drm_client_release:
> > > -       drm_client_release(&ifbdev->helper.client);
> > >   err_drm_fb_helper_unprepare:
> > >          drm_fb_helper_unprepare(&ifbdev->helper);
> > > +       mutex_destroy(&ifbdev->hpd_lock);
> > >          kfree(ifbdev);
> > > -       return ret;
> > > -}
> > > -
> > > -static void intel_fbdev_initial_config(void *data,
> > > async_cookie_t
> > > cookie)
> > > -{
> > > -       struct intel_fbdev *ifbdev = data;
> > > -
> > > -       /* Due to peculiar init order wrt to hpd handling this is
> > > separate. */
> > > -       if (drm_fb_helper_initial_config(&ifbdev->helper))
> > > -               intel_fbdev_unregister(to_i915(ifbdev-
> > > >helper.dev));
> > > -}
> > > -
> > > -void intel_fbdev_initial_config_async(struct drm_i915_private
> > > *dev_priv)
> > > -{
> > > -       struct intel_fbdev *ifbdev = dev_priv-
> > > >display.fbdev.fbdev;
> > > -
> > > -       if (!ifbdev)
> > > -               return;
> > > -
> > > -       ifbdev->cookie =
> > > async_schedule(intel_fbdev_initial_config,
> > > ifbdev);
> > > -}
> > > -
> > > -void intel_fbdev_unregister(struct drm_i915_private *dev_priv)
> > > -{
> > > -       struct intel_fbdev *ifbdev = dev_priv-
> > > >display.fbdev.fbdev;
> > > -
> > > -       if (!ifbdev)
> > > -               return;
> > > -
> > > -       intel_fbdev_set_suspend(&dev_priv->drm,
> > > FBINFO_STATE_SUSPENDED, true);
> > > -
> > > -       if (!current_is_async())
> > > -               intel_fbdev_sync(ifbdev);
> > > -
> > > -       drm_fb_helper_unregister_info(&ifbdev->helper);
> > > -}
> > > -
> > > -void intel_fbdev_fini(struct drm_i915_private *dev_priv)
> > > -{
> > > -       struct intel_fbdev *ifbdev = fetch_and_zero(&dev_priv-
> > > > display.fbdev.fbdev);
> > > -
> > > -       if (!ifbdev)
> > > -               return;
> > > -
> > > -       intel_fbdev_destroy(ifbdev);
> > >   }
> > >   
> > >   struct intel_framebuffer *intel_fbdev_framebuffer(struct
> > > intel_fbdev
> > > *fbdev)
> > > diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.h
> > > b/drivers/gpu/drm/i915/display/intel_fbdev.h
> > > index 8c953f102ba22..08de2d5b34338 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_fbdev.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_fbdev.h
> > > @@ -14,27 +14,11 @@ struct intel_fbdev;
> > >   struct intel_framebuffer;
> > >   
> > >   #ifdef CONFIG_DRM_FBDEV_EMULATION
> > > -int intel_fbdev_init(struct drm_device *dev);
> > > -void intel_fbdev_initial_config_async(struct drm_i915_private
> > > *dev_priv);
> > > -void intel_fbdev_unregister(struct drm_i915_private *dev_priv);
> > > -void intel_fbdev_fini(struct drm_i915_private *dev_priv);
> > > +void intel_fbdev_setup(struct drm_i915_private *dev_priv);
> > >   void intel_fbdev_set_suspend(struct drm_device *dev, int state,
> > > bool
> > > synchronous);
> > >   struct intel_framebuffer *intel_fbdev_framebuffer(struct
> > > intel_fbdev
> > > *fbdev);
> > >   #else
> > > -static inline int intel_fbdev_init(struct drm_device *dev)
> > > -{
> > > -       return 0;
> > > -}
> > > -
> > > -static inline void intel_fbdev_initial_config_async(struct
> > > drm_i915_private *dev_priv)
> > > -{
> > > -}
> > > -
> > > -static inline void intel_fbdev_unregister(struct
> > > drm_i915_private
> > > *dev_priv)
> > > -{
> > > -}
> > > -
> > > -static inline void intel_fbdev_fini(struct drm_i915_private
> > > *dev_priv)
> > > +static inline void intel_fbdev_setup(struct drm_i915_private
> > > *dev_priv)
> > >   {
> > >   }
> > >   
> > > diff --git a/drivers/gpu/drm/xe/display/xe_display.c
> > > b/drivers/gpu/drm/xe/display/xe_display.c
> > > index cdbc3f04c80a7..ca5cbe1d8a03b 100644
> > > --- a/drivers/gpu/drm/xe/display/xe_display.c
> > > +++ b/drivers/gpu/drm/xe/display/xe_display.c
> > > @@ -214,9 +214,7 @@ void xe_display_fini(struct xe_device *xe)
> > >          if (!xe->info.enable_display)
> > >                  return;
> > >   
> > > -       /* poll work can call into fbdev, hence clean that up
> > > afterwards */
> > >          intel_hpd_poll_fini(xe);
> > > -       intel_fbdev_fini(xe);
> > >   
> > >          intel_hdcp_component_fini(xe);
> > >          intel_audio_deinit(xe);
> 



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