On Wed, May 7, 2014 at 1:14 PM, Seung-Woo Kim <sw0312.kim@xxxxxxxxxxx> wrote: > Hi Daniel, > > On 2014년 05월 05일 00:26, Daniel Kurtz wrote: >> Mixer hardware supports offsetting dma from start of source buffer using >> the MXR_GRP_SXY register. >> >> Signed-off-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx> >> --- >> drivers/gpu/drm/exynos/exynos_mixer.c | 8 +++----- >> 1 file changed, 3 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/gpu/drm/exynos/exynos_mixer.c b/drivers/gpu/drm/exynos/exynos_mixer.c >> index 475eb49..40cf39b 100644 >> --- a/drivers/gpu/drm/exynos/exynos_mixer.c >> +++ b/drivers/gpu/drm/exynos/exynos_mixer.c >> @@ -529,13 +529,11 @@ static void mixer_graph_buffer(struct mixer_context *ctx, int win) >> >> dst_x_offset = win_data->crtc_x; >> dst_y_offset = win_data->crtc_y; >> + src_x_offset = win_data->fb_x; >> + src_y_offset = win_data->fb_y; >> >> /* converting dma address base and source offset */ >> - dma_addr = win_data->dma_addr >> - + (win_data->fb_x * win_data->bpp >> 3) >> - + (win_data->fb_y * win_data->fb_width * win_data->bpp >> 3); >> - src_x_offset = 0; >> - src_y_offset = 0; >> + dma_addr = win_data->dma_addr; > > Basically, you are right and source offset register can be used. But > because of limitation of resolution for mixer up to 1920x1080, I > considered modified soruce dma address to set one frame buffer, which is > bigger than 1920x1080, on to both fimd and hdmi. Hi Seung-Woo, I do not see why the maximum MIXER resolution matters for choosing between offsetting BASE or using SXY. Let's say you have one big 1920x1908 framebuffer, with a span of 1920, starting at dma_addr (there is no extra padding at the end of the line). Let's say you wanted the mixer to scan out 1920x1080 pixels starting from (0, 800) in the framebuffer, and start drawing them at (0,0) on the screen. What we currently do is: BASE = dma_addr + (800 * 1080 * 4) SPAN = 1920 SXY = SX(0) | SY(0) WH = W(1920) | H(1080) DXY = DX(0) | DY(0) I am proposing we do: BASE = dma_addr SPAN = 1920 SXY = SX(0) | SY(800) WH = W(1920) | H(1080) DXY = DX(0) | DY(0) In both cases, the mixer resolution is 1920x1080. My motivation for wanting to program an un-modified dma_addr into BASE is so we can then just check BASE_S to determine from which buffer the mixer is actively being scanned out without worrying about the source offset, since the source offset can change for a given framebuffer (for example, when doing panning, or if an overlay is used for a HW cursor). Best Regards, -Daniel > > Regards, > - Seung-Woo Kim > >> >> if (win_data->scan_flags & DRM_MODE_FLAG_INTERLACE) >> ctx->interlace = true; >> > > -- > Seung-Woo Kim > Samsung Software R&D Center > -- > -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html