On Tue, May 9, 2023 at 10:14 AM Marek Vasut <marex@xxxxxxx> wrote:
>
> On 5/8/23 07:57, Liu Ying wrote:
>
> Hi,
Hi,
>
> > diff --git a/drivers/gpu/drm/mxsfb/lcdif_kms.c b/drivers/gpu/drm/mxsfb/lcdif_kms.c
> > index 262bc43b1079..e54200a9fcb9 100644
> > --- a/drivers/gpu/drm/mxsfb/lcdif_kms.c
> > +++ b/drivers/gpu/drm/mxsfb/lcdif_kms.c
> > @@ -394,7 +394,7 @@ static void lcdif_crtc_mode_set_nofb(struct lcdif_drm_private *lcdif,
> > struct drm_display_mode *m = &lcdif->crtc.state->adjusted_mode;
> > u32 bus_flags = 0;
> >
> > - if (lcdif->bridge && lcdif->bridge->timings)
> > + if (lcdif->bridge->timings)
> > bus_flags = lcdif->bridge->timings->input_bus_flags;
> > else if (bridge_state)
> > bus_flags = bridge_state->input_bus_cfg.flags;
> > @@ -463,30 +463,21 @@ static void lcdif_crtc_atomic_enable(struct drm_crtc *crtc,
> > struct drm_display_mode *m = &lcdif->crtc.state->adjusted_mode;
> > struct drm_bridge_state *bridge_state = NULL;
> > struct drm_device *drm = lcdif->drm;
> > - u32 bus_format = 0;
> > + u32 bus_format;
> > dma_addr_t paddr;
> >
> > - /* If there is a bridge attached to the LCDIF, use its bus format */
> > - if (lcdif->bridge) {
> > - bridge_state =
> > - drm_atomic_get_new_bridge_state(state,
> > - lcdif->bridge);
> > - if (!bridge_state)
> > - bus_format = MEDIA_BUS_FMT_FIXED;
> > - else
> > - bus_format = bridge_state->input_bus_cfg.format;
> > -
> > - if (bus_format == MEDIA_BUS_FMT_FIXED) {
> > - dev_warn_once(drm->dev,
> > - "Bridge does not provide bus format, assuming MEDIA_BUS_FMT_RGB888_1X24.\n"
> > - "Please fix bridge driver by handling atomic_get_input_bus_fmts.\n");
> > - bus_format = MEDIA_BUS_FMT_RGB888_1X24;
> > - }
> > - }
> > + bridge_state = drm_atomic_get_new_bridge_state(state, lcdif->bridge);
> > + if (!bridge_state)
> > + bus_format = MEDIA_BUS_FMT_FIXED;
> > + else
> > + bus_format = bridge_state->input_bus_cfg.format;
>
> The code below seems to change the logic slightly.
>
> Could it happen that:
> - bridge_state is valid (i.e. non-NULL)
> - bridge_state->input_bus_cfg.format is set to 0 (i.e. not set) ?
> (note that MEDIA_BUS_FMT_FIXED is defined as 0x0001)
Yes, bridge_state->input_bus_cfg.format could be zero.
Will keep the below default MEDIA_BUS_FMT_RGB888_1X24
bus format setting in next version.
Regards,
Liu Ying
>
> > - /* If all else fails, default to RGB888_1X24 */
> > - if (!bus_format)
> > + if (bus_format == MEDIA_BUS_FMT_FIXED) {
> > + dev_warn_once(drm->dev,
> > + "Bridge does not provide bus format, assuming MEDIA_BUS_FMT_RGB888_1X24.\n"
> > + "Please fix bridge driver by handling atomic_get_input_bus_fmts.\n");
> > bus_format = MEDIA_BUS_FMT_RGB888_1X24;
> > + }
> >
> > clk_set_rate(lcdif->clk, m->crtc_clock * 1000);
>
> [...]
