[Intel-gfx] [PATCH v5 7/7] drm/i915: Implement fbdev emulation as in-kernel client
Hogander, Jouni
jouni.hogander at intel.com
Wed Oct 25 11:36:28 UTC 2023
Hi Thomas, couple of minor comments and a question below.
On Wed, 2023-09-27 at 12:26 +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 i915_fbdev_setup() after i915 has registered its
intel_fbdev_setup
> DRM device. Just like similar code in other drivers, i915 fbdev
> emulation now acts as a regular DRM client.
>
> 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_dev_unregister() releases the client 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.
>
> 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>
> ---
> drivers/gpu/drm/i915/display/intel_display.c | 1 -
> .../drm/i915/display/intel_display_driver.c | 18 --
> drivers/gpu/drm/i915/display/intel_fbdev.c | 180 ++++++++--------
> --
> drivers/gpu/drm/i915/display/intel_fbdev.h | 20 +-
> drivers/gpu/drm/i915/i915_driver.c | 2 +
> 5 files changed, 83 insertions(+), 138 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> b/drivers/gpu/drm/i915/display/intel_display.c
> index edbcf5968804d..7efa8d2787c39 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -81,7 +81,6 @@
> #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 ffdcddd1943e0..213a4ee93ffc2 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_driver.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_driver.c
> @@ -364,10 +364,6 @@ 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);
> intel_hpd_poll_disable(i915);
> @@ -392,16 +388,6 @@ 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
> @@ -445,9 +431,6 @@ 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 */
> @@ -484,7 +467,6 @@ void intel_display_driver_unregister(struct
> drm_i915_private *i915)
> if (!HAS_DISPLAY(i915))
> return;
>
> - intel_fbdev_unregister(i915);
> intel_audio_deinit(i915);
>
> /*
> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev.c
> b/drivers/gpu/drm/i915/display/intel_fbdev.c
> index 39de61d4e7906..100a4aaf1b7e4 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);
> +}
> +
> static const struct fb_ops intelfb_ops = {
> .owner = THIS_MODULE,
> __FB_DEFAULT_DEFERRED_OPS_RDWR(intel_fbdev),
> @@ -144,6 +163,7 @@ 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,
> };
>
> static int intelfb_alloc(struct drm_fb_helper *helper,
> @@ -212,7 +232,6 @@ 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);
> struct i915_ggtt *ggtt = to_gt(dev_priv)->ggtt;
> const struct i915_gtt_view view = {
> .type = I915_GTT_VIEW_NORMAL,
> @@ -337,7 +356,7 @@ 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:
> @@ -363,26 +382,6 @@ 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,
> @@ -546,16 +545,6 @@ 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.
> @@ -646,8 +635,6 @@ static void
> intel_fbdev_output_poll_changed(struct drm_device *dev)
> if (!ifbdev)
> return;
>
> - intel_fbdev_sync(ifbdev);
> -
> mutex_lock(&ifbdev->hpd_lock);
> send_hpd = !ifbdev->hpd_suspended;
> ifbdev->hpd_waiting = true;
> @@ -664,7 +651,6 @@ static void intel_fbdev_restore_mode(struct
> drm_i915_private *dev_priv)
> if (!ifbdev)
> return;
>
> - intel_fbdev_sync(ifbdev);
> if (!ifbdev->vma)
> return;
>
> @@ -677,7 +663,20 @@ static void 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)
> {
> @@ -691,9 +690,36 @@ static int intel_fbdev_client_restore(struct
> drm_client_dev *client)
>
> static int intel_fbdev_client_hotplug(struct drm_client_dev *client)
> {
> - 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) {
> + intel_fbdev_output_poll_changed(dev);
> + return 0;
> + }
> +
> + ret = drm_fb_helper_init(dev, fb_helper);
> + if (ret)
> + goto err_drm_err;
> +
> + if (!drm_drv_uses_atomic_modeset(dev))
> + drm_helper_disable_unused_functions(dev);
Can you please explain why this is needed here?
> +
> + 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 = {
> @@ -703,22 +729,23 @@ 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 *dev_priv)
Use i915 rather than dev_priv.
BR,
Jouni Högander
> {
> - struct drm_i915_private *dev_priv = to_i915(dev);
> + struct drm_device *dev = &dev_priv->drm;
> struct intel_fbdev *ifbdev;
> int ret;
>
> - if (drm_WARN_ON(dev, !HAS_DISPLAY(dev_priv)))
> - return -ENODEV;
> + if (!HAS_DISPLAY(dev_priv))
> + 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);
>
> + dev_priv->display.fbdev.fbdev = ifbdev;
> + INIT_WORK(&dev_priv->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
> @@ -726,68 +753,19 @@ int intel_fbdev_init(struct drm_device *dev)
>
> ret = drm_client_init(dev, &ifbdev->helper.client, "i915-
> 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/i915/i915_driver.c
> b/drivers/gpu/drm/i915/i915_driver.c
> index 86460cd8167d1..53663c0cc3be4 100644
> --- a/drivers/gpu/drm/i915/i915_driver.c
> +++ b/drivers/gpu/drm/i915/i915_driver.c
> @@ -817,6 +817,8 @@ int i915_driver_probe(struct pci_dev *pdev, const
> struct pci_device_id *ent)
>
> i915->do_release = true;
>
> + intel_fbdev_setup(i915);
> +
> return 0;
>
> out_cleanup_gem:
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