2023-05-10 09:41:30

by Liu Ying

Subject: [PATCH v6 2/6] drm: lcdif: Drop unnecessary NULL pointer check on lcdif->bridge

A valid bridge is already found in lcdif_attach_bridge() and set
to lcdif->bridge, so lcdif->bridge cannot be a NULL pointer. Drop
the unnecessary NULL pointer check in KMS stage.

Tested-by: Alexander Stein <[email protected]>
Reviewed-by: Alexander Stein <[email protected]>
Signed-off-by: Liu Ying <[email protected]>
---
v5->v6:
* Keep default MEDIA_BUS_FMT_RGB888_1X24 bus format in case
bridge_state->input_bus_cfg.format is zero. (Marek)

v4->v5:
* Add Alexander's T-b tag.

v3->v4:
* Add Alexander's R-b tag.

v2->v3:
* No change.

v1->v2:
* Split from patch 2/2 in v1. (Marek, Alexander)

drivers/gpu/drm/mxsfb/lcdif_kms.c | 36 +++++++++++++------------------
1 file changed, 15 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/mxsfb/lcdif_kms.c b/drivers/gpu/drm/mxsfb/lcdif_kms.c
index 262bc43b1079..ba00a155d9b6 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 +463,24 @@ 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;

- /* 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;
+ } else if (!bus_format) {
+ /* If all else fails, default to RGB888_1X24 */
+ bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+ }

clk_set_rate(lcdif->clk, m->crtc_clock * 1000);

--
2.37.1

2023-05-10 16:36:17

by Marek Vasut

Subject: Re: [PATCH v6 2/6] drm: lcdif: Drop unnecessary NULL pointer check on lcdif->bridge

On 5/10/23 11:24, Liu Ying wrote:
> A valid bridge is already found in lcdif_attach_bridge() and set
> to lcdif->bridge, so lcdif->bridge cannot be a NULL pointer. Drop
> the unnecessary NULL pointer check in KMS stage.
>
> Tested-by: Alexander Stein <[email protected]>
> Reviewed-by: Alexander Stein <[email protected]>
> Signed-off-by: Liu Ying <[email protected]>

Reviewed-by: Marek Vasut <[email protected]>