4.20-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
commit d179b88deb3bf6fed4991a31fd6f0f2cad21fab5 upstream.
If we skipped all the connectors that were not part of a tile, we would
leave conn_seq=0 and conn_configured=0, convincing ourselves that we
had stagnated in our configuration attempts. Avoid this situation by
starting conn_seq=ALL_CONNECTORS, and repeating until we find no more
connectors to configure.
Fixes: 754a76591b12 ("drm/i915/fbdev: Stop repeating tile configuration on stagnation")
Reported-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20190215123019.32283-1-chris@xxxxxxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx> # v3.19+
(cherry picked from commit d9b308b1f8a1acc0c3279f443d4fe0f9f663252e)
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/intel_fbdev.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
--- a/drivers/gpu/drm/i915/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/intel_fbdev.c
@@ -336,8 +336,8 @@ 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, conn_seq, mask;
unsigned int count = min(fb_helper->connector_count, BITS_PER_LONG);
+ unsigned long conn_configured, conn_seq;
int i, j;
bool *save_enabled;
bool fallback = true, ret = true;
@@ -355,10 +355,9 @@ static bool intel_fb_initial_config(stru
drm_modeset_backoff(&ctx);
memcpy(save_enabled, enabled, count);
- mask = GENMASK(count - 1, 0);
+ conn_seq = GENMASK(count - 1, 0);
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;
@@ -371,7 +370,8 @@ retry:
if (conn_configured & BIT(i))
continue;
- if (conn_seq == 0 && !connector->has_tile)
+ /* First pass, only consider tiled connectors */
+ if (conn_seq == GENMASK(count - 1, 0) && !connector->has_tile)
continue;
if (connector->status == connector_status_connected)
@@ -475,8 +475,10 @@ retry:
conn_configured |= BIT(i);
}
- if ((conn_configured & mask) != mask && conn_configured != conn_seq)
+ if (conn_configured != conn_seq) { /* repeat until no more are found */
+ conn_seq = conn_configured;
goto retry;
+ }
/*
* If the BIOS didn't enable everything it could, fall back to have the
