On Thu, Dec 12, 2013 at 12:41:54PM -0800, Jesse Barnes wrote:
> Retrieve current framebuffer config info from the regs and create an fb
> object for the buffer the BIOS or boot loader left us. This should
> allow for smooth transitions to userspace apps once we finish the
> initial configuration construction.
>
> v2: check for non-native modes and adjust (Jesse)
> fixup aperture and cmap frees (Imre)
> use unlocked unref if init_bios fails (Jesse)
> fix curly brace around DSPADDR check (Imre)
> comment failure path for pin_and_fence (Imre)
> v3: fixup fixup of aperture frees (Chris)
> v4: update to current bits (locking & pin_and_fence hack) (Jesse)
> v5: move fb config fetch to display code (Jesse)
> re-order hw state readout on initial load to suit fb inherit (Jesse)
> re-add pin_and_fence in fbdev code to make sure we refcount properly (Je
> v6: rename to plane_config (Daniel)
> check for valid object when initializing BIOS fb (Jesse)
> split from plane_config readout and other display changes (Jesse)
> drop use_bios_fb option (Chris)
> update comments (Jesse)
> rework fbdev_init_bios for clarity (Jesse)
> drop fb obj ref under lock (Chris)
> v7: use fb object from plane_config instead (Ville)
> take ref on fb object (Jesse)
>
> Signed-off-by: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
Ok, I've thought through the lifetime rules for the fbcon takeover and I
think we need some more polish for that. I also think we could simplify
the inital_config logic quite a bit. More comments below.
Cheers, Daniel
> ---
> drivers/gpu/drm/i915/intel_display.c | 4 +-
> drivers/gpu/drm/i915/intel_drv.h | 4 +-
> drivers/gpu/drm/i915/intel_fbdev.c | 235 ++++++++++++++++++++++++++++++++---
> 3 files changed, 224 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 94183af..b868331 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -7817,11 +7817,11 @@ mode_fits_in_fbdev(struct drm_device *dev,
> if (dev_priv->fbdev == NULL)
> return NULL;
>
> - obj = dev_priv->fbdev->ifb.obj;
> + obj = dev_priv->fbdev->fb->obj;
> if (obj == NULL)
> return NULL;
>
> - fb = &dev_priv->fbdev->ifb.base;
> + fb = &dev_priv->fbdev->fb->base;
> if (fb->pitches[0] < intel_framebuffer_pitch_for_width(mode->hdisplay,
> fb->bits_per_pixel))
> return NULL;
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 4787773..5f9182e 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -110,9 +110,10 @@ struct intel_framebuffer {
>
> struct intel_fbdev {
> struct drm_fb_helper helper;
> - struct intel_framebuffer ifb;
> + struct intel_framebuffer *fb;
> struct list_head fbdev_list;
> struct drm_display_mode *our_mode;
> + int preferred_bpp;
> };
>
> struct intel_encoder {
> @@ -671,6 +672,7 @@ int intel_framebuffer_init(struct drm_device *dev,
> struct intel_framebuffer *ifb,
> struct drm_mode_fb_cmd2 *mode_cmd,
> struct drm_i915_gem_object *obj);
> +void intel_fbdev_init_bios(struct drm_device *dev);
> void intel_framebuffer_fini(struct intel_framebuffer *fb);
> void intel_prepare_page_flip(struct drm_device *dev, int plane);
> void intel_finish_page_flip(struct drm_device *dev, int pipe);
> diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
> index 284c3eb..db75f22 100644
> --- a/drivers/gpu/drm/i915/intel_fbdev.c
> +++ b/drivers/gpu/drm/i915/intel_fbdev.c
> @@ -62,11 +62,20 @@ static int intelfb_alloc(struct drm_fb_helper *helper,
> {
> struct intel_fbdev *ifbdev =
> container_of(helper, struct intel_fbdev, helper);
> + struct intel_framebuffer *fb;
> struct drm_device *dev = helper->dev;
> struct drm_mode_fb_cmd2 mode_cmd = {};
> struct drm_i915_gem_object *obj;
> int size, ret;
>
> + fb = kzalloc(sizeof(*fb), GFP_KERNEL);
> + if (!fb) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + ifbdev->fb = fb;
> +
> /* we don't do packed 24bpp */
> if (sizes->surface_bpp == 24)
> sizes->surface_bpp = 32;
> @@ -97,7 +106,7 @@ static int intelfb_alloc(struct drm_fb_helper *helper,
> goto out_unref;
> }
>
> - ret = intel_framebuffer_init(dev, &ifbdev->ifb, &mode_cmd, obj);
> + ret = intel_framebuffer_init(dev, ifbdev->fb, &mode_cmd, obj);
> if (ret)
> goto out_unpin;
>
> @@ -116,7 +125,7 @@ static int intelfb_create(struct drm_fb_helper *helper,
> {
> struct intel_fbdev *ifbdev =
> container_of(helper, struct intel_fbdev, helper);
> - struct intel_framebuffer *intel_fb = &ifbdev->ifb;
> + struct intel_framebuffer *intel_fb = ifbdev->fb;
> struct drm_device *dev = helper->dev;
> struct drm_i915_private *dev_priv = dev->dev_private;
> struct fb_info *info;
> @@ -148,7 +157,7 @@ static int intelfb_create(struct drm_fb_helper *helper,
>
> info->par = helper;
>
> - fb = &ifbdev->ifb.base;
> + fb = &ifbdev->fb->base;
>
> ifbdev->helper.fb = fb;
> ifbdev->helper.fbdev = info;
> @@ -194,14 +203,14 @@ static int intelfb_create(struct drm_fb_helper *helper,
> * If the object is stolen however, it will be full of whatever
> * garbage was left in there.
> */
> - if (ifbdev->ifb.obj->stolen)
> + if (ifbdev->fb->obj->stolen)
> memset_io(info->screen_base, 0, info->screen_size);
>
> /* Use default scratch pixmap (info->pixmap.flags = FB_PIXMAP_SYSTEM) */
>
> - DRM_DEBUG_KMS("allocated %dx%d fb: 0x%08lx, bo %p\n",
> + DRM_DEBUG_KMS("allocated %dx%d fb: map %p, bo %p, size 0x%lx\n",
> fb->width, fb->height,
> - i915_gem_obj_ggtt_offset(obj), obj);
> + info->screen_base, obj, info->screen_size);
>
> mutex_unlock(&dev->struct_mutex);
> vga_switcheroo_client_fb_set(dev->pdev, info);
> @@ -236,6 +245,96 @@ static void intel_crtc_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
> *blue = intel_crtc->lut_b[regno] << 8;
> }
>
> +static struct drm_fb_helper_crtc *
> +intel_fb_helper_crtc(struct drm_fb_helper *fb_helper, struct drm_crtc *crtc)
> +{
> + int i;
> +
> + for (i = 0; i < fb_helper->crtc_count; i++)
> + if (fb_helper->crtc_info[i].mode_set.crtc == crtc)
> + return &fb_helper->crtc_info[i];
> +
> + return NULL;
> +}
> +
> +/*
> + * Try to read the BIOS display configuration and use it for the initial
> + * fb configuration.
> + *
> + * The BIOS or boot loader will generally create an initial display
> + * configuration for us that includes some set of active pipes and displays.
> + * This routine tries to figure out which pipes and connectors are active
> + * and stuffs them into the crtcs and modes array given to us by the
> + * drm_fb_helper code.
> + *
> + * The overall sequence is:
> + * intel_fbdev_init - from driver load
> + * intel_fbdev_init_bios - initialize the intel_fbdev using BIOS data
> + * drm_fb_helper_init - build fb helper structs
> + * drm_fb_helper_single_add_all_connectors - more fb helper structs
> + * intel_fbdev_initial_config - apply the config
> + * drm_fb_helper_initial_config - call ->probe then register_framebuffer()
> + * drm_setup_crtcs - build crtc config for fbdev
> + * intel_fb_initial_config - find active connectors etc
> + * drm_fb_helper_single_fb_probe - set up fbdev
> + * intelfb_create - re-use or alloc fb, build out fbdev structs
> + *
> + * If the BIOS or boot loader leaves the display in VGA mode, there's not
> + * much we can do; switching out of that mode involves allocating a new,
> + * high res buffer, and also recalculating bandwidth requirements for the
> + * new bpp configuration.
> + */
> +static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
> + struct drm_fb_helper_crtc **crtcs,
> + struct drm_display_mode **modes,
> + bool *enabled, int width, int height)
> +{
> + int i;
> +
> + for (i = 0; i < fb_helper->connector_count; i++) {
> + struct drm_connector *connector;
> + struct drm_encoder *encoder;
> +
> + connector = fb_helper->connector_info[i]->connector;
> + if (!enabled[i]) {
> + DRM_DEBUG_KMS("connector %d not enabled, skipping\n",
> + connector->base.id);
> + continue;
> + }
> +
> + encoder = connector->encoder;
> + if (!encoder || !encoder->crtc) {
> + DRM_DEBUG_KMS("connector %d has no encoder or crtc, skipping\n",
> + connector->base.id);
> + continue;
> + }
> +
> + if (WARN_ON(!encoder->crtc->enabled)) {
> + DRM_DEBUG_KMS("connector %s on crtc %d has inconsistent state, aborting\n",
> + drm_get_connector_name(connector),
> + encoder->crtc->base.id);
> + return false;
> + }
> +
> + if (!to_intel_crtc(encoder->crtc)->active) {
> + DRM_DEBUG_KMS("connector %s on inactive crtc %d, borting\n",
> + drm_get_connector_name(connector),
> + encoder->crtc->base.id);
> + return false;
> + }
> +
> + modes[i] = &encoder->crtc->mode;
> + crtcs[i] = intel_fb_helper_crtc(fb_helper, encoder->crtc);
> +
> + DRM_DEBUG_KMS("connector %s on crtc %d: %s\n",
> + drm_get_connector_name(connector),
> + encoder->crtc->base.id,
> + modes[i]->name);
> + }
> +
> + return true;
> +}
> +
> static struct drm_fb_helper_funcs intel_fb_helper_funcs = {
> .gamma_set = intel_crtc_fb_gamma_set,
> .gamma_get = intel_crtc_fb_gamma_get,
> @@ -258,8 +357,102 @@ static void intel_fbdev_destroy(struct drm_device *dev,
>
> drm_fb_helper_fini(&ifbdev->helper);
>
> - drm_framebuffer_unregister_private(&ifbdev->ifb.base);
> - intel_framebuffer_fini(&ifbdev->ifb);
> + drm_framebuffer_unregister_private(&ifbdev->fb->base);
> + intel_framebuffer_fini(ifbdev->fb);
> + kfree(ifbdev->fb);
> +}
> +
> +/*
> + * Build an intel_fbdev struct using a BIOS allocated framebuffer, if possible.
> + * The core display code will have read out the current plane configuration,
> + * so we use that to figure out if there's an object for us to use as the
> + * fb, and if so, we re-use it for the fbdev configuration.
> + *
> + * Note we only support a single fb shared across pipes for boot (mostly for
> + * fbcon), so we just find the biggest and use that.
> + */
> +void intel_fbdev_init_bios(struct drm_device *dev)
> +{
> + struct drm_i915_private *dev_priv = dev->dev_private;
> + struct intel_fbdev *ifbdev;
> + struct intel_framebuffer *fb = NULL;
> + struct drm_crtc *crtc;
> + struct intel_crtc *intel_crtc;
> + struct intel_plane_config *plane_config = NULL;
> + unsigned int last_size = 0;
> +
> + ifbdev = kzalloc(sizeof(struct intel_fbdev), GFP_KERNEL);
> + if (ifbdev == NULL) {
> + DRM_DEBUG_KMS("failed to alloc intel fbdev\n");
> + return;
> + }
> +
> + /* Find the largest framebuffer to use, then free the others */
> + list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
> + intel_crtc = to_intel_crtc(crtc);
> +
> + if (!intel_crtc->active || !intel_crtc->plane_config.fb->obj) {
> + DRM_DEBUG_KMS("pipe %c not active or no fb, skipping\n",
> + pipe_name(intel_crtc->pipe));
> + continue;
> + }
> +
> + if (intel_crtc->plane_config.size > last_size) {
> + plane_config = &intel_crtc->plane_config;
> + last_size = plane_config->size;
> + fb = plane_config->fb;
> + }
> + }
> +
> + /* Free unused fbs */
> + list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
> + struct intel_framebuffer *cur_fb;
> +
> + intel_crtc = to_intel_crtc(crtc);
> + cur_fb = intel_crtc->plane_config.fb;
> +
> + if (cur_fb && cur_fb != fb)
> + intel_framebuffer_fini(cur_fb);
> + }
> +
> + if (!fb) {
> + DRM_DEBUG_KMS("no active pipes found, not using BIOS config\n");
> + goto out_free;
> + }
> +
> + ifbdev->preferred_bpp = plane_config->fb->base.bits_per_pixel;
> + ifbdev->helper.funcs = &intel_fb_helper_funcs;
> + ifbdev->helper.funcs->initial_config = intel_fb_initial_config;
This here is a bit surprising - my model of operation here presumed that
if we correctly assign the crtc->fb and the ifbdev->fb pointers we could
fully rely on the fastboot setcrtc logic to eschew the modeset.
Being the ever-vary of special-purpose logic I'd much prefer this implicit
approach - otherwise we have one more special case to care about in the
fastboot=y/n and CONFIG_FB=y/n matrix.
So have you tried to ditch this special initial_config functions
(obviously only looks good with fastboot=1) or what precise corner-case
does this fix?
> + ifbdev->fb = fb;
> +
> + /* Assuming a single fb across all pipes here */
> + list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
> + intel_crtc = to_intel_crtc(crtc);
> +
> + if (!intel_crtc->active)
> + continue;
> +
> + /*
> + * This should only fail on the first one so we don't need
> + * to cleanup any secondary crtc->fbs
> + */
> + if (intel_pin_and_fence_fb_obj(dev, fb->obj, NULL))
> + goto out_unref_obj;
> +
> + crtc->fb = &fb->base;
> + drm_gem_object_reference(&fb->obj->base);
> + drm_framebuffer_reference(&fb->base);
As mentioned I think this part here needs to be moved to the earlier
plane_config reconstruction loop.
But checking the fb refcounting now it looks like we leak the initial
references that the plane_config struct holds (or I didn't spot it). And
we miss the reference for ifbdev->fb when stealing the bios framebuffer.
With the current code of using
intel_framebuffer_fini(ifbdev->fb);
kfree(ifbdev->fb);
You get away with this since the kfree will ignore the surplus references
from the plane_config. But if you replace this with the
drm_framebuffer_unreference call like I've suggested we'll have a real
leak. So I think this needs to be fixed.
> + }
> +
> + dev_priv->fbdev = ifbdev;
> +
> + DRM_DEBUG_KMS("using BIOS fb for initial console\n");
> + return;
> +
> +out_unref_obj:
> + intel_framebuffer_fini(fb);
> +out_free:
> + kfree(ifbdev);
> }
>
> int intel_fbdev_init(struct drm_device *dev)
> @@ -268,17 +461,25 @@ int intel_fbdev_init(struct drm_device *dev)
> struct drm_i915_private *dev_priv = dev->dev_private;
> int ret;
>
> - ifbdev = kzalloc(sizeof(*ifbdev), GFP_KERNEL);
> - if (!ifbdev)
> - return -ENOMEM;
> + /* This may fail, if so, dev_priv->fbdev won't be set below */
> + intel_fbdev_init_bios(dev);
>
> - dev_priv->fbdev = ifbdev;
> - ifbdev->helper.funcs = &intel_fb_helper_funcs;
> + if ((ifbdev = dev_priv->fbdev) == NULL) {
> + ifbdev = kzalloc(sizeof(struct intel_fbdev), GFP_KERNEL);
> + if (ifbdev == NULL)
> + return -ENOMEM;
> +
> + ifbdev->helper.funcs = &intel_fb_helper_funcs;
> + ifbdev->preferred_bpp = 32;
> +
> + dev_priv->fbdev = ifbdev;
> + }
>
> ret = drm_fb_helper_init(dev, &ifbdev->helper,
> INTEL_INFO(dev)->num_pipes,
> 4);
> if (ret) {
> + dev_priv->fbdev = NULL;
> kfree(ifbdev);
> return ret;
> }
> @@ -291,9 +492,10 @@ int intel_fbdev_init(struct drm_device *dev)
> void intel_fbdev_initial_config(struct drm_device *dev)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
> + struct intel_fbdev *ifbdev = dev_priv->fbdev;
>
> /* Due to peculiar init order wrt to hpd handling this is separate. */
> - drm_fb_helper_initial_config(&dev_priv->fbdev->helper, 32);
> + drm_fb_helper_initial_config(&ifbdev->helper, ifbdev->preferred_bpp);
> }
>
> void intel_fbdev_fini(struct drm_device *dev)
> @@ -322,7 +524,7 @@ void intel_fbdev_set_suspend(struct drm_device *dev, int state)
> * been restored from swap. If the object is stolen however, it will be
> * full of whatever garbage was left in there.
> */
> - if (state == FBINFO_STATE_RUNNING && ifbdev->ifb.obj->stolen)
> + if (state == FBINFO_STATE_RUNNING && ifbdev->fb->obj->stolen)
> memset_io(info->screen_base, 0, info->screen_size);
>
> fb_set_suspend(info, state);
> @@ -333,7 +535,8 @@ MODULE_LICENSE("GPL and additional rights");
> void intel_fbdev_output_poll_changed(struct drm_device *dev)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
> - drm_fb_helper_hotplug_event(&dev_priv->fbdev->helper);
> + if (dev_priv->fbdev)
> + drm_fb_helper_hotplug_event(&dev_priv->fbdev->helper);
> }
>
> void intel_fbdev_restore_mode(struct drm_device *dev)
> --
> 1.8.4.2
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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