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-lapt...
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 Signed-off-by: Hans de Goede hdegoede@redhat.com --- drivers/gpu/drm/i915/intel_dsi_vbt.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_dsi_vbt.c b/drivers/gpu/drm/i915/intel_dsi_vbt.c index 022bf59418df..a2a9b9d0eeaa 100644 --- a/drivers/gpu/drm/i915/intel_dsi_vbt.c +++ b/drivers/gpu/drm/i915/intel_dsi_vbt.c @@ -895,6 +895,17 @@ 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;
On Fri, May 24, 2019 at 07:40:28PM +0200, Hans de Goede wrote:
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-lapt...
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 Signed-off-by: Hans de Goede hdegoede@redhat.com
drivers/gpu/drm/i915/intel_dsi_vbt.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_dsi_vbt.c b/drivers/gpu/drm/i915/intel_dsi_vbt.c index 022bf59418df..a2a9b9d0eeaa 100644 --- a/drivers/gpu/drm/i915/intel_dsi_vbt.c +++ b/drivers/gpu/drm/i915/intel_dsi_vbt.c @@ -895,6 +895,17 @@ 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;
Maybe should squash these patches together to make the stable backport less painful?
Anyways, seems OK to me. Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com
if (mipi_config->target_burst_mode_freq < bitrate) { DRM_ERROR("Burst mode freq is less than computed\n"); return false;-- 2.21.0
Hi,
Thank you for the reviews.
On 04-06-19 19:29, Ville Syrjälä wrote:
On Fri, May 24, 2019 at 07:40:28PM +0200, Hans de Goede wrote:
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-lapt...
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 Signed-off-by: Hans de Goede hdegoede@redhat.com
drivers/gpu/drm/i915/intel_dsi_vbt.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_dsi_vbt.c b/drivers/gpu/drm/i915/intel_dsi_vbt.c index 022bf59418df..a2a9b9d0eeaa 100644 --- a/drivers/gpu/drm/i915/intel_dsi_vbt.c +++ b/drivers/gpu/drm/i915/intel_dsi_vbt.c @@ -895,6 +895,17 @@ 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;Maybe should squash these patches together to make the stable backport less painful?
Good idea, done.
Anyways, seems OK to me. Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com
And pushed with your Reviewed-by.
Regards,
Hans
linux-stable-mirror@lists.linaro.org
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Hans de Goede -
Ville Syrjälä