The patch below does not apply to the 6.0-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

Possible dependencies:

3c1ea6a5f4f5 ("drm/i915: Remove non-existent pipes from bigjoiner pipe mask")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 3c1ea6a5f4f55d4e376675dda16945eb5d9bb4de Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= ville.syrjala@linux.intel.com Date: Fri, 18 Nov 2022 20:52:01 +0200 Subject: [PATCH] drm/i915: Remove non-existent pipes from bigjoiner pipe mask MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

bigjoiner_pipes() doesn't consider that: - RKL only has three pipes - some pipes may be fused off

This means that intel_atomic_check_bigjoiner() won't reject all configurations that would need a non-existent pipe. Instead we just keep on rolling witout actually having reserved the slave pipe we need.

It's possible that we don't outright explode anywhere due to this since eg. for_each_intel_crtc_in_pipe_mask() will only walk the crtcs we've registered even though the passed in pipe_mask asks for more of them. But clearly the thing won't do what is expected of it when the required pipes are not present.

Fix the problem by consulting the device info pipe_mask already in bigjoiner_pipes().

Cc: stable@vger.kernel.org Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20221118185201.10469-1-ville.s... Reviewed-by: Arun R Murthy arun.r.murthy@intel.com (cherry picked from commit f1c87a94a1087a26f41007ee83264033007421b5) Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c index 461c62c88413..de77054195c6 100644 --- a/drivers/gpu/drm/i915/display/intel_display.c +++ b/drivers/gpu/drm/i915/display/intel_display.c @@ -3723,12 +3723,16 @@ static bool ilk_get_pipe_config(struct intel_crtc *crtc,

static u8 bigjoiner_pipes(struct drm_i915_private *i915) { + u8 pipes; + if (DISPLAY_VER(i915) >= 12) - return BIT(PIPE_A) | BIT(PIPE_B) | BIT(PIPE_C) | BIT(PIPE_D); + pipes = BIT(PIPE_A) | BIT(PIPE_B) | BIT(PIPE_C) | BIT(PIPE_D); else if (DISPLAY_VER(i915) >= 11) - return BIT(PIPE_B) | BIT(PIPE_C); + pipes = BIT(PIPE_B) | BIT(PIPE_C); else - return 0; + pipes = 0; + + return pipes & RUNTIME_INFO(i915)->pipe_mask; }

static bool transcoder_ddi_func_is_enabled(struct drm_i915_private *dev_priv,