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authorHans de Goede <hdegoede@redhat.com>2019-05-24 19:40:27 +0200
committerHans de Goede <hdegoede@redhat.com>2019-06-05 18:24:00 +0200
commit2c1c55252647abd989b94f725b190c700312d053 (patch)
tree5bea89f359e9a8b09f1584ed8bf0dd33357d2292
parentf41c615310d2f4f20f6259ae254bc058f61ced6d (diff)
drm/i915/dsi: Use a fuzzy check for burst mode clock check
Prior to this commit we fail to init the DSI panel on the GPD MicroPC: https://www.indiegogo.com/projects/gpd-micropc-6-inch-handheld-industry-laptop#/ The problem is intel_dsi_vbt_init() failing with the following error: *ERROR* Burst mode freq is less than computed The pclk in the VBT panel modeline is 70000, together with 24 bpp and 4 lines this results in a bitrate value of 70000 * 24 / 4 = 420000. But the target_burst_mode_freq in the VBT is 418000. This commit works around this problem by adding an intel_fuzzy_clock_check when target_burst_mode_freq < bitrate and setting target_burst_mode_freq to bitrate when that checks succeeds, fixing the panel not working. Cc: stable@vger.kernel.org Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190524174028.21659-2-hdegoede@redhat.com
-rw-r--r--drivers/gpu/drm/i915/intel_display.c2
-rw-r--r--drivers/gpu/drm/i915/intel_drv.h1
-rw-r--r--drivers/gpu/drm/i915/intel_dsi_vbt.c11
3 files changed, 13 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 122a075b6174..1560030563b6 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12163,7 +12163,7 @@ encoder_retry:
return 0;
}
-static bool intel_fuzzy_clock_check(int clock1, int clock2)
+bool intel_fuzzy_clock_check(int clock1, int clock2)
{
int diff;
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 0dcc03592d6e..d0aeb383024a 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1557,6 +1557,7 @@ int vlv_force_pll_on(struct drm_i915_private *dev_priv, enum pipe pipe,
const struct dpll *dpll);
void vlv_force_pll_off(struct drm_i915_private *dev_priv, enum pipe pipe);
int lpt_get_iclkip(struct drm_i915_private *dev_priv);
+bool intel_fuzzy_clock_check(int clock1, int clock2);
/* modesetting asserts */
void assert_panel_unlocked(struct drm_i915_private *dev_priv,
diff --git a/drivers/gpu/drm/i915/intel_dsi_vbt.c b/drivers/gpu/drm/i915/intel_dsi_vbt.c
index fbed9064ac7e..7cdde1d04f4b 100644
--- a/drivers/gpu/drm/i915/intel_dsi_vbt.c
+++ b/drivers/gpu/drm/i915/intel_dsi_vbt.c
@@ -858,6 +858,17 @@ bool intel_dsi_vbt_init(struct intel_dsi *intel_dsi, u16 panel_id)
if (mipi_config->target_burst_mode_freq) {
u32 bitrate = intel_dsi_bitrate(intel_dsi);
+ /*
+ * Sometimes the VBT contains a slightly lower clock,
+ * then the bitrate we have calculated, in this case
+ * just replace it with the calculated bitrate.
+ */
+ if (mipi_config->target_burst_mode_freq < bitrate &&
+ intel_fuzzy_clock_check(
+ mipi_config->target_burst_mode_freq,
+ bitrate))
+ mipi_config->target_burst_mode_freq = bitrate;
+
if (mipi_config->target_burst_mode_freq < bitrate) {
DRM_ERROR("Burst mode freq is less than computed\n");
return false;