Re: [PATCH 3/7] drm/format-helper: Add drm_fb_xrgb8888_to_rgb888()

On Tue, Aug 17, 2021 at 02:29:13PM +0200, Noralf Trønnes wrote:

Add XRGB8888 emulation support for devices that can only do RGB888.

Cc: Thomas Zimmermann tzimmermann@suse.de Signed-off-by: Noralf Trønnes noralf@tronnes.org

---

drivers/gpu/drm/drm_format_helper.c | 38 +++++++++++++++++++++++++++++ include/drm/drm_format_helper.h | 2 ++ 2 files changed, 40 insertions(+)

diff --git a/drivers/gpu/drm/drm_format_helper.c b/drivers/gpu/drm/drm_format_helper.c index 53b426da7467..c42d50315123 100644 --- a/drivers/gpu/drm/drm_format_helper.c +++ b/drivers/gpu/drm/drm_format_helper.c @@ -297,6 +297,44 @@ static void drm_fb_xrgb8888_to_rgb888_line(u8 *dbuf, u32 *sbuf, } }

+/**

• • drm_fb_xrgb8888_to_rgb888 - Convert XRGB8888 to RGB888 clip buffer
• • @dst: RGB888 destination buffer
• • @src: XRGB8888 source buffer
• • @fb: DRM framebuffer
• • @clip: Clip rectangle area to copy
• • Drivers can use this function for RGB888 devices that don't natively
• • support XRGB8888.
• • This function does not apply clipping on dst, i.e. the destination
• • is a small buffer containing the clip rect only.
• */

+void drm_fb_xrgb8888_to_rgb888(void *dst, void *src, struct drm_framebuffer *fb,

• 	       struct drm_rect *clip)
  

I do wonder whether we really need all the combinations here. E.g. if we allow dst_pitch == 0 and just automatically pick this one here, and then paper over the __iomem differences with dma_buf_map we wouldn't need two different functions.

Just an idea.

Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch

+{

• size_t width = drm_rect_width(clip);
• size_t src_len = width * sizeof(u32);
• unsigned int y;
• void *sbuf;
• /* Use a buffer to speed up access on buffers with uncached read mapping (i.e. WC) */
• sbuf = kmalloc(src_len, GFP_KERNEL);
• if (!sbuf)

• return;
  

• src += clip_offset(clip, fb->pitches[0], sizeof(u32));
• for (y = 0; y < drm_rect_height(clip); y++) {

• memcpy(sbuf, src, src_len);
  

• drm_fb_xrgb8888_to_rgb888_line(dst, sbuf, width);
  

• src += fb->pitches[0];
  

• dst += width * 3;
  

• }
• kfree(sbuf);

+} +EXPORT_SYMBOL(drm_fb_xrgb8888_to_rgb888);

/**

• drm_fb_xrgb8888_to_rgb888_dstclip - Convert XRGB8888 to RGB888 clip buffer
• @dst: RGB565 destination buffer (iomem)

diff --git a/include/drm/drm_format_helper.h b/include/drm/drm_format_helper.h index d0809aff5cf8..e86925cf07b9 100644 --- a/include/drm/drm_format_helper.h +++ b/include/drm/drm_format_helper.h @@ -24,6 +24,8 @@ void drm_fb_xrgb8888_to_rgb565(void *dst, void *vaddr, void drm_fb_xrgb8888_to_rgb565_dstclip(void __iomem *dst, unsigned int dst_pitch, void *vaddr, struct drm_framebuffer *fb, struct drm_rect *clip, bool swab); +void drm_fb_xrgb8888_to_rgb888(void *dst, void *src, struct drm_framebuffer *fb,

• 	       struct drm_rect *clip);
  

void drm_fb_xrgb8888_to_rgb888_dstclip(void __iomem *dst, unsigned int dst_pitch, void *vaddr, struct drm_framebuffer *fb, struct drm_rect *clip); -- 2.32.0