| Message ID | 20190524130607.4021-1-hdegoede@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915/dsi: Use a fuzzy check for burst mode clock check | expand |
Hi, On 5/24/19 3:06 PM, 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-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 > Signed-off-by: Hans de Goede <hdegoede@redhat.com> I just realized that this patch depends on a patch from another series of mine which exports intel_fuzzy_clock_check, I will resend this as a series with the patch doing the exporting as first patch, so that the CI can test this. Regards, Hans > --- > 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; >
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;
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 Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- drivers/gpu/drm/i915/intel_dsi_vbt.c | 11 +++++++++++ 1 file changed, 11 insertions(+)