[PATCH 4.10 03/29] drm/i915/fbdev: Stop repeating tile configuration on stagnation

From: Greg Kroah-Hartman
Date: Sun Apr 16 2017 - 04:09:01 EST


4.10-stable review patch. If anyone has any objections, please let me know.

------------------

From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>

commit b717a0392530ae8da0da041abe5c3a6098b55660 upstream.

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>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/gpu/drm/i915/intel_fbdev.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

--- 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(stru
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(stru
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 @@ retry:
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 @@ retry:
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