On Thu, 17 Aug 2017, Jani Nikula <jani.nikula@xxxxxxxxx> wrote: > Sometimes it would be most enlightening to debug systems by replacing > the VBT to be used. For example, in the referenced bug the BIOS provides > different VBT depending on the boot mode (UEFI vs. legacy). It would be > interesting to try the failing boot mode with the VBT from the working > boot, and see if that makes a difference. > > Add a module parameter to load the VBT using the firmware loader, not > unlike the EDID firmware mechanism. > > As a starting point for experimenting, one can pick up the BIOS provided > VBT from /sys/kernel/debug/dri/0/i915_opregion/i915_vbt. > > v2: clarify firmware load return value check (Bob) > > v3: kfree the loaded firmware blob > > References: https://bugs.freedesktop.org/show_bug.cgi?id=97822#c83 > Reviewed-by: Bob Paauwe <bob.j.paauwe@xxxxxxxxx> > Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> And pushed, with Daniel's additional irc ack. BR, Jani. > --- > drivers/gpu/drm/i915/i915_drv.h | 1 + > drivers/gpu/drm/i915/i915_params.c | 4 ++++ > drivers/gpu/drm/i915/i915_params.h | 1 + > drivers/gpu/drm/i915/intel_opregion.c | 45 +++++++++++++++++++++++++++++++++++ > 4 files changed, 51 insertions(+) > > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index 6c25c8520c87..3ee4fd2a9b41 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -646,6 +646,7 @@ struct intel_opregion { > u32 swsci_sbcb_sub_functions; > struct opregion_asle *asle; > void *rvda; > + void *vbt_firmware; > const void *vbt; > u32 vbt_size; > u32 *lid_state; > diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c > index 14e2c2e57f96..8ab003dca113 100644 > --- a/drivers/gpu/drm/i915/i915_params.c > +++ b/drivers/gpu/drm/i915/i915_params.c > @@ -118,6 +118,10 @@ MODULE_PARM_DESC(vbt_sdvo_panel_type, > module_param_named_unsafe(reset, i915.reset, int, 0600); > MODULE_PARM_DESC(reset, "Attempt GPU resets (0=disabled, 1=full gpu reset, 2=engine reset [default])"); > > +module_param_named_unsafe(vbt_firmware, i915.vbt_firmware, charp, 0400); > +MODULE_PARM_DESC(vbt_firmware, > + "Load VBT from specified file under /lib/firmware"); > + > #if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR) > module_param_named(error_capture, i915.error_capture, bool, 0600); > MODULE_PARM_DESC(error_capture, > diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.h > index febbfdbd30bd..ac844709c97e 100644 > --- a/drivers/gpu/drm/i915/i915_params.h > +++ b/drivers/gpu/drm/i915/i915_params.h > @@ -28,6 +28,7 @@ > #include <linux/cache.h> /* for __read_mostly */ > > #define I915_PARAMS_FOR_EACH(func) \ > + func(char *, vbt_firmware); \ > func(int, modeset); \ > func(int, panel_ignore_lid); \ > func(int, semaphores); \ > diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c > index 2bd03001cc70..98154efcb2f4 100644 > --- a/drivers/gpu/drm/i915/intel_opregion.c > +++ b/drivers/gpu/drm/i915/intel_opregion.c > @@ -27,6 +27,7 @@ > > #include <linux/acpi.h> > #include <linux/dmi.h> > +#include <linux/firmware.h> > #include <acpi/video.h> > > #include <drm/drmP.h> > @@ -829,6 +830,10 @@ void intel_opregion_unregister(struct drm_i915_private *dev_priv) > memunmap(opregion->rvda); > opregion->rvda = NULL; > } > + if (opregion->vbt_firmware) { > + kfree(opregion->vbt_firmware); > + opregion->vbt_firmware = NULL; > + } > opregion->header = NULL; > opregion->acpi = NULL; > opregion->swsci = NULL; > @@ -912,6 +917,43 @@ static const struct dmi_system_id intel_no_opregion_vbt[] = { > { } > }; > > +static int intel_load_vbt_firmware(struct drm_i915_private *dev_priv) > +{ > + struct intel_opregion *opregion = &dev_priv->opregion; > + const struct firmware *fw = NULL; > + const char *name = i915.vbt_firmware; > + int ret; > + > + if (!name || !*name) > + return -ENOENT; > + > + ret = request_firmware(&fw, name, &dev_priv->drm.pdev->dev); > + if (ret) { > + DRM_ERROR("Requesting VBT firmware \"%s\" failed (%d)\n", > + name, ret); > + return ret; > + } > + > + if (intel_bios_is_valid_vbt(fw->data, fw->size)) { > + opregion->vbt_firmware = kmemdup(fw->data, fw->size, GFP_KERNEL); > + if (opregion->vbt_firmware) { > + DRM_DEBUG_KMS("Found valid VBT firmware \"%s\"\n", name); > + opregion->vbt = opregion->vbt_firmware; > + opregion->vbt_size = fw->size; > + ret = 0; > + } else { > + ret = -ENOMEM; > + } > + } else { > + DRM_DEBUG_KMS("Invalid VBT firmware \"%s\"\n", name); > + ret = -EINVAL; > + } > + > + release_firmware(fw); > + > + return ret; > +} > + > int intel_opregion_setup(struct drm_i915_private *dev_priv) > { > struct intel_opregion *opregion = &dev_priv->opregion; > @@ -974,6 +1016,9 @@ int intel_opregion_setup(struct drm_i915_private *dev_priv) > if (mboxes & MBOX_ASLE_EXT) > DRM_DEBUG_DRIVER("ASLE extension supported\n"); > > + if (intel_load_vbt_firmware(dev_priv) == 0) > + goto out; > + > if (dmi_check_system(intel_no_opregion_vbt)) > goto out; -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
