The patch below does not apply to the 4.9-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@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b717a0392530ae8da0da041abe5c3a6098b55660 Mon Sep 17 00:00:00 2001 From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Date: Fri, 24 Feb 2017 11:43:06 +0000 Subject: [PATCH] drm/i915/fbdev: Stop repeating tile configuration on stagnation If we cease making progress in finding matching outputs for a tiled configuration, stop looping over the remaining unconfigured outputs. v2: Use conn_seq (instead of pass) to only apply tile configuration on first pass. Fixes: b0ee9e7fa5b4 ("drm/fb: add support for tiled monitor configurations. (v2)") Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Tomasz Lis <tomasz.lis@xxxxxxxxx> Cc: Dave Airlie <airlied@xxxxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxxx> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> Cc: Sean Paul <seanpaul@xxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # v3.19+ Reviewed-by: Tomasz Lis <tomasz.lis@xxxxxxxxx> Link: http://patchwork.freedesktop.org/patch/msgid/20170224114306.4400-1-chris@xxxxxxxxxxxxxxxxxx (cherry picked from commit 754a76591b12c88f57ad8b4ca533a5c9566a1922) Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c index 1b8ba2e77539..2d449fb5d1d2 100644 --- a/drivers/gpu/drm/i915/intel_fbdev.c +++ b/drivers/gpu/drm/i915/intel_fbdev.c @@ -357,14 +357,13 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper, bool *enabled, int width, int height) { struct drm_i915_private *dev_priv = to_i915(fb_helper->dev); - unsigned long conn_configured, mask; + unsigned long conn_configured, conn_seq, mask; unsigned int count = min(fb_helper->connector_count, BITS_PER_LONG); int i, j; bool *save_enabled; bool fallback = true; int num_connectors_enabled = 0; int num_connectors_detected = 0; - int pass = 0; save_enabled = kcalloc(count, sizeof(bool), GFP_KERNEL); if (!save_enabled) @@ -374,6 +373,7 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper, mask = BIT(count) - 1; conn_configured = 0; retry: + conn_seq = conn_configured; for (i = 0; i < count; i++) { struct drm_fb_helper_connector *fb_conn; struct drm_connector *connector; @@ -387,7 +387,7 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper, if (conn_configured & BIT(i)) continue; - if (pass == 0 && !connector->has_tile) + if (conn_seq == 0 && !connector->has_tile) continue; if (connector->status == connector_status_connected) @@ -498,10 +498,8 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper, conn_configured |= BIT(i); } - if ((conn_configured & mask) != mask) { - pass++; + if ((conn_configured & mask) != mask && conn_configured != conn_seq) goto retry; - } /* * If the BIOS didn't enable everything it could, fall back to have the