On Wed, Mar 13, 2013 at 11:21:01AM -0700, Ben Widawsky wrote:
> GEN supports a fusing option which subtracts the PCH display (making the
> CPU display also useless). In this configuration MMIO which gets decoded
> to a certain range will hang the CPU.
>
> For us, this is sort of the equivalent of having no pipes, and we can
> easily modify some code to not do certain things with no pipes.
>
> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
> ---
> drivers/gpu/drm/i915/i915_dma.c | 20 ++++++++++++++------
> drivers/gpu/drm/i915/intel_crt.c | 3 +++
> drivers/gpu/drm/i915/intel_display.c | 10 ++++++++--
> drivers/gpu/drm/i915/intel_fb.c | 3 +++
> drivers/gpu/drm/i915/intel_overlay.c | 3 +++
> 5 files changed, 31 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
> index ebcfe2e..d925504 100644
> --- a/drivers/gpu/drm/i915/i915_dma.c
> +++ b/drivers/gpu/drm/i915/i915_dma.c
> @@ -1322,6 +1322,10 @@ static int i915_load_modeset_init(struct drm_device *dev)
> /* Always safe in the mode setting case. */
> /* FIXME: do pre/post-mode set stuff in core KMS code */
> dev->vblank_disable_allowed = 1;
> + if (INTEL_INFO(dev)->num_pipes == 0) {
> + dev_priv->mm.suspended = 0;
> + return 0;
> + }
>
> ret = intel_fbdev_init(dev);
> if (ret)
> @@ -1630,9 +1634,11 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
> mutex_init(&dev_priv->rps.hw_lock);
> mutex_init(&dev_priv->modeset_restore_lock);
>
> - ret = drm_vblank_init(dev, INTEL_INFO(dev)->num_pipes);
> - if (ret)
> - goto out_gem_unload;
> + if (INTEL_INFO(dev)->num_pipes) {
> + ret = drm_vblank_init(dev, INTEL_INFO(dev)->num_pipes);
> + if (ret)
> + goto out_gem_unload;
> + }
>
> /* Start out suspended */
> dev_priv->mm.suspended = 1;
> @@ -1647,9 +1653,11 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
>
> i915_setup_sysfs(dev);
>
> - /* Must be done after probing outputs */
> - intel_opregion_init(dev);
> - acpi_video_register();
> + if (INTEL_INFO(dev)->num_pipes) {
> + /* Must be done after probing outputs */
> + intel_opregion_init(dev);
> + acpi_video_register();
> + }
>
> if (IS_GEN5(dev))
> intel_gpu_ips_init(dev_priv);
> diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
> index cfc9687..e794c6c 100644
> --- a/drivers/gpu/drm/i915/intel_crt.c
> +++ b/drivers/gpu/drm/i915/intel_crt.c
> @@ -736,6 +736,9 @@ void intel_crt_init(struct drm_device *dev)
> if (dmi_check_system(intel_no_crt))
> return;
>
> + if (INTEL_INFO(dev)->num_pipes == 0)
> + return;
Imo better to move this up in the callchain since we should never ever
bother to probe connectors with no pipes.
> +
> crt = kzalloc(sizeof(struct intel_crt), GFP_KERNEL);
> if (!crt)
> return;
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 23379e7..d6dbffd 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -7682,6 +7682,9 @@ intel_modeset_check_state(struct drm_device *dev)
> struct intel_encoder *encoder;
> struct intel_connector *connector;
>
> + if (INTEL_INFO(dev)->num_pipes == 0)
> + return;
Presuming our works correctly this should never be called if there's no
pipes. Could be that the lid handler is offending us, but that one
shouldn't be registered without a panel. Can you please check whether we
really need this?
> +
> list_for_each_entry(connector, &dev->mode_config.connector_list,
> base.head) {
> /* This also checks the encoder/connector hw state with the
> @@ -8326,7 +8329,9 @@ static void intel_setup_outputs(struct drm_device *dev)
> if (!(HAS_DDI(dev) && (I915_READ(DDI_BUF_CTL(PORT_A)) & DDI_A_4_LANES)))
> intel_crt_init(dev);
>
> - if (HAS_DDI(dev)) {
> + if (INTEL_INFO(dev)->num_pipes == 0) {
> + DRM_DEBUG_KMS("Skipping output detection\n");
Move this up and add an early return, then all the other output checks
should be redundant. There's some other stuff called from
intel_modeset_init which might need to be guarded.
> + } else if (HAS_DDI(dev)) {
> int found;
>
> /* Haswell uses DDI functions to detect digital outputs */
> @@ -8443,7 +8448,8 @@ static void intel_setup_outputs(struct drm_device *dev)
>
> intel_init_pch_refclk(dev);
If you drop everything in setup_outputs you also don't have to deal with
the pch_refclock stuff.
Cheers, Daniel
> - drm_helper_move_panel_connectors_to_head(dev);
> + if (INTEL_INFO(dev)->num_pipes)
> + drm_helper_move_panel_connectors_to_head(dev);
> }
>
> static void intel_user_framebuffer_destroy(struct drm_framebuffer *fb)
> diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c
> index dcdb1d3..5f825c2 100644
> --- a/drivers/gpu/drm/i915/intel_fb.c
> +++ b/drivers/gpu/drm/i915/intel_fb.c
> @@ -295,6 +295,9 @@ void intel_fb_restore_mode(struct drm_device *dev)
> struct drm_mode_config *config = &dev->mode_config;
> struct drm_plane *plane;
>
> + if (!INTEL_INFO(dev)->num_pipes)
> + return;
> +
> drm_modeset_lock_all(dev);
>
> ret = drm_fb_helper_restore_fbdev_mode(&dev_priv->fbdev->helper);
> diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c
> index 67a2501..e7fbf2e 100644
> --- a/drivers/gpu/drm/i915/intel_overlay.c
> +++ b/drivers/gpu/drm/i915/intel_overlay.c
> @@ -1323,6 +1323,9 @@ void intel_setup_overlay(struct drm_device *dev)
> if (!HAS_OVERLAY(dev))
> return;
>
> + if (INTEL_INFO(dev)->num_pipes == 0)
> + return;
> +
> overlay = kzalloc(sizeof(struct intel_overlay), GFP_KERNEL);
> if (!overlay)
> return;
> --
> 1.8.1.5
>
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--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
