| Message ID | 20230311231007.46174-1-aford173@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/bridge: adv7533: Fix adv7533_mode_valid for adv7533 and adv7535 | expand |
On 12/03/2023 01:10, Adam Ford wrote: > When dynamically switching lanes was removed, the intent of the code > was to check to make sure that higher speed items used 4 lanes, but > it had the unintended consequence of removing the slower speeds for > 4-lane users. > > This attempts to remedy this by doing a check to see that the > max frequency doesn't exceed the chip limit, and a second > check to make sure that the max bit-rate doesn't exceed the > number of lanes * max bit rate / lane. > > Fixes: 9a0cdcd6649b ("drm/bridge: adv7533: remove dynamic lane switching from adv7533 bridge") > Please remove the empty line here. There should be no empty lines between the tags > Signed-off-by: Adam Ford <aford173@gmail.com> > > diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c b/drivers/gpu/drm/bridge/adv7511/adv7533.c > index fdfeadcefe80..10a112d36945 100644 > --- a/drivers/gpu/drm/bridge/adv7511/adv7533.c > +++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c > @@ -103,13 +103,9 @@ void adv7533_dsi_power_off(struct adv7511 *adv) > enum drm_mode_status adv7533_mode_valid(struct adv7511 *adv, > const struct drm_display_mode *mode) > { > - int lanes; > + unsigned long max_lane_freq; > struct mipi_dsi_device *dsi = adv->dsi; > - > - if (mode->clock > 80000) > - lanes = 4; > - else > - lanes = 3; > + u8 bpp = mipi_dsi_pixel_format_to_bpp(dsi->format); > > /* > * TODO: add support for dynamic switching of lanes Drop the comment please. It makes little sense with your new implementation. > @@ -117,8 +113,16 @@ enum drm_mode_status adv7533_mode_valid(struct adv7511 *adv, > * out the modes which shall need different number of lanes > * than what was configured in the device tree. > */ > - if (lanes != dsi->lanes) > - return MODE_BAD; > + > + /* Check max clock for either 7533 or 7535 */ > + if (mode->clock > (adv->type == ADV7533 ? 80000 : 148500)) > + return MODE_CLOCK_HIGH; > + > + /* Check max clock for each lane */ > + max_lane_freq = (adv->type == ADV7533 ? 800000 : 891000); > + > + if (mode->clock * bpp > max_lane_freq * adv->num_dsi_lanes) > + return MODE_CLOCK_HIGH; > > return MODE_OK; > }
On Sun, Mar 12, 2023 at 2:10 AM Dmitry Baryshkov <dmitry.baryshkov@linaro.org> wrote: > > On 12/03/2023 01:10, Adam Ford wrote: > > When dynamically switching lanes was removed, the intent of the code > > was to check to make sure that higher speed items used 4 lanes, but > > it had the unintended consequence of removing the slower speeds for > > 4-lane users. > > > > This attempts to remedy this by doing a check to see that the > > max frequency doesn't exceed the chip limit, and a second > > check to make sure that the max bit-rate doesn't exceed the > > number of lanes * max bit rate / lane. > > > > Fixes: 9a0cdcd6649b ("drm/bridge: adv7533: remove dynamic lane switching from adv7533 bridge") > > > > Please remove the empty line here. There should be no empty lines > between the tags > > > > Signed-off-by: Adam Ford <aford173@gmail.com> > > > > diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c b/drivers/gpu/drm/bridge/adv7511/adv7533.c > > index fdfeadcefe80..10a112d36945 100644 > > --- a/drivers/gpu/drm/bridge/adv7511/adv7533.c > > +++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c > > @@ -103,13 +103,9 @@ void adv7533_dsi_power_off(struct adv7511 *adv) > > enum drm_mode_status adv7533_mode_valid(struct adv7511 *adv, > > const struct drm_display_mode *mode) > > { > > - int lanes; > > + unsigned long max_lane_freq; > > struct mipi_dsi_device *dsi = adv->dsi; > > - > > - if (mode->clock > 80000) > > - lanes = 4; > > - else > > - lanes = 3; > > + u8 bpp = mipi_dsi_pixel_format_to_bpp(dsi->format); > > > > /* > > * TODO: add support for dynamic switching of lanes > > Drop the comment please. It makes little sense with your new implementation. > > > @@ -117,8 +113,16 @@ enum drm_mode_status adv7533_mode_valid(struct adv7511 *adv, > > * out the modes which shall need different number of lanes > > * than what was configured in the device tree. > > */ > > - if (lanes != dsi->lanes) > > - return MODE_BAD; > > + > > + /* Check max clock for either 7533 or 7535 */ > > + if (mode->clock > (adv->type == ADV7533 ? 80000 : 148500)) > > + return MODE_CLOCK_HIGH; > > + > > + /* Check max clock for each lane */ > > + max_lane_freq = (adv->type == ADV7533 ? 800000 : 891000); > > + > > + if (mode->clock * bpp > max_lane_freq * adv->num_dsi_lanes) > > + return MODE_CLOCK_HIGH; > > > > return MODE_OK; > > } > > -- > With best wishes > Dmitry > With Dmitrys feedback, feel free to add my Reviewed-by.
diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c b/drivers/gpu/drm/bridge/adv7511/adv7533.c index fdfeadcefe80..10a112d36945 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7533.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c @@ -103,13 +103,9 @@ void adv7533_dsi_power_off(struct adv7511 *adv) enum drm_mode_status adv7533_mode_valid(struct adv7511 *adv, const struct drm_display_mode *mode) { - int lanes; + unsigned long max_lane_freq; struct mipi_dsi_device *dsi = adv->dsi; - - if (mode->clock > 80000) - lanes = 4; - else - lanes = 3; + u8 bpp = mipi_dsi_pixel_format_to_bpp(dsi->format); /* * TODO: add support for dynamic switching of lanes @@ -117,8 +113,16 @@ enum drm_mode_status adv7533_mode_valid(struct adv7511 *adv, * out the modes which shall need different number of lanes * than what was configured in the device tree. */ - if (lanes != dsi->lanes) - return MODE_BAD; + + /* Check max clock for either 7533 or 7535 */ + if (mode->clock > (adv->type == ADV7533 ? 80000 : 148500)) + return MODE_CLOCK_HIGH; + + /* Check max clock for each lane */ + max_lane_freq = (adv->type == ADV7533 ? 800000 : 891000); + + if (mode->clock * bpp > max_lane_freq * adv->num_dsi_lanes) + return MODE_CLOCK_HIGH; return MODE_OK; }
When dynamically switching lanes was removed, the intent of the code was to check to make sure that higher speed items used 4 lanes, but it had the unintended consequence of removing the slower speeds for 4-lane users. This attempts to remedy this by doing a check to see that the max frequency doesn't exceed the chip limit, and a second check to make sure that the max bit-rate doesn't exceed the number of lanes * max bit rate / lane. Fixes: 9a0cdcd6649b ("drm/bridge: adv7533: remove dynamic lane switching from adv7533 bridge") Signed-off-by: Adam Ford <aford173@gmail.com>