The fb_videomode structure stores the front porch and back porch in the right_margin and left_margin fields respectively. right_margin should thus be computed with hsync_start - hdisplay, and left_margin with htotal - hsync_end. The same holds for the vertical direction.
Active Front Sync Back Region Porch Porch <-------------------><----------------><-------------><---------------->
//////////////////| ////////////////// | ////////////////// |.................. .................. _______________
<------ xres -------><- right_margin -><- hsync_len -><- left_margin -->
<---- hdisplay -----> <------------ hsync_start ------------> <--------------------- hsync_end --------------------> <--------------------------------- htotal ----------------------------->
Fix the fb_videomode <-> drm_mode_modeinfo conversion functions accordingly.
Signed-off-by: Laurent Pinchart laurent.pinchart@ideasonboard.com --- drivers/gpu/drm/exynos/exynos_drm_connector.c | 16 ++++++++-------- 1 files changed, 8 insertions(+), 8 deletions(-)
While trying to understand how the fb_videomode and drm_mode_modeinfo fields map to each other, I found what might be a bug in the Exynos DRM driver. Could you please check and confirm that my understanding is correct ?
diff --git a/drivers/gpu/drm/exynos/exynos_drm_connector.c b/drivers/gpu/drm/exynos/exynos_drm_connector.c index d620b07..7bb1dca 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_connector.c +++ b/drivers/gpu/drm/exynos/exynos_drm_connector.c @@ -52,14 +52,14 @@ convert_to_display_mode(struct drm_display_mode *mode, mode->vrefresh = timing->refresh;
mode->hdisplay = timing->xres; - mode->hsync_start = mode->hdisplay + timing->left_margin; + mode->hsync_start = mode->hdisplay + timing->right_margin; mode->hsync_end = mode->hsync_start + timing->hsync_len; - mode->htotal = mode->hsync_end + timing->right_margin; + mode->htotal = mode->hsync_end + timing->left_margin;
mode->vdisplay = timing->yres; - mode->vsync_start = mode->vdisplay + timing->upper_margin; + mode->vsync_start = mode->vdisplay + timing->lower_margin; mode->vsync_end = mode->vsync_start + timing->vsync_len; - mode->vtotal = mode->vsync_end + timing->lower_margin; + mode->vtotal = mode->vsync_end + timing->upper_margin;
if (timing->vmode & FB_VMODE_INTERLACED) mode->flags |= DRM_MODE_FLAG_INTERLACE; @@ -81,14 +81,14 @@ convert_to_video_timing(struct fb_videomode *timing, timing->refresh = drm_mode_vrefresh(mode);
timing->xres = mode->hdisplay; - timing->left_margin = mode->hsync_start - mode->hdisplay; + timing->right_margin = mode->hsync_start - mode->hdisplay; timing->hsync_len = mode->hsync_end - mode->hsync_start; - timing->right_margin = mode->htotal - mode->hsync_end; + timing->left_margin = mode->htotal - mode->hsync_end;
timing->yres = mode->vdisplay; - timing->upper_margin = mode->vsync_start - mode->vdisplay; + timing->lower_margin = mode->vsync_start - mode->vdisplay; timing->vsync_len = mode->vsync_end - mode->vsync_start; - timing->lower_margin = mode->vtotal - mode->vsync_end; + timing->upper_margin = mode->vtotal - mode->vsync_end;
if (mode->flags & DRM_MODE_FLAG_INTERLACE) timing->vmode = FB_VMODE_INTERLACED;
On 03/08/2012 08:34 PM, Laurent Pinchart wrote:
The fb_videomode structure stores the front porch and back porch in the right_margin and left_margin fields respectively. right_margin should thus be computed with hsync_start - hdisplay, and left_margin with htotal - hsync_end. The same holds for the vertical direction.
Active Front Sync Back Region Porch Porch<-------------------><----------------><-------------><---------------->
//////////////////| ////////////////// | ////////////////// |.................. .................. _______________
<------ xres -------><- right_margin -><- hsync_len -><- left_margin -->
<---- hdisplay -----> <------------ hsync_start ------------> <--------------------- hsync_end --------------------> <--------------------------------- htotal ----------------------------->
Fix the fb_videomode<-> drm_mode_modeinfo conversion functions accordingly.
Signed-off-by: Laurent Pinchartlaurent.pinchart@ideasonboard.com
drivers/gpu/drm/exynos/exynos_drm_connector.c | 16 ++++++++-------- 1 files changed, 8 insertions(+), 8 deletions(-)
While trying to understand how the fb_videomode and drm_mode_modeinfo fields map to each other, I found what might be a bug in the Exynos DRM driver. Could you please check and confirm that my understanding is correct ?
Good catch. You can refer Documentation/fb/framebuffer.txt to know in detail.
Acked-by: Joonyoung Shim jy0922.shim@samsung.com
Thanks.
diff --git a/drivers/gpu/drm/exynos/exynos_drm_connector.c b/drivers/gpu/drm/exynos/exynos_drm_connector.c index d620b07..7bb1dca 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_connector.c +++ b/drivers/gpu/drm/exynos/exynos_drm_connector.c @@ -52,14 +52,14 @@ convert_to_display_mode(struct drm_display_mode *mode, mode->vrefresh = timing->refresh;
mode->hdisplay = timing->xres;
- mode->hsync_start = mode->hdisplay + timing->left_margin;
- mode->hsync_start = mode->hdisplay + timing->right_margin; mode->hsync_end = mode->hsync_start + timing->hsync_len;
- mode->htotal = mode->hsync_end + timing->right_margin;
mode->htotal = mode->hsync_end + timing->left_margin;
mode->vdisplay = timing->yres;
- mode->vsync_start = mode->vdisplay + timing->upper_margin;
- mode->vsync_start = mode->vdisplay + timing->lower_margin; mode->vsync_end = mode->vsync_start + timing->vsync_len;
- mode->vtotal = mode->vsync_end + timing->lower_margin;
mode->vtotal = mode->vsync_end + timing->upper_margin;
if (timing->vmode& FB_VMODE_INTERLACED) mode->flags |= DRM_MODE_FLAG_INTERLACE;
@@ -81,14 +81,14 @@ convert_to_video_timing(struct fb_videomode *timing, timing->refresh = drm_mode_vrefresh(mode);
timing->xres = mode->hdisplay;
- timing->left_margin = mode->hsync_start - mode->hdisplay;
- timing->right_margin = mode->hsync_start - mode->hdisplay; timing->hsync_len = mode->hsync_end - mode->hsync_start;
- timing->right_margin = mode->htotal - mode->hsync_end;
timing->left_margin = mode->htotal - mode->hsync_end;
timing->yres = mode->vdisplay;
- timing->upper_margin = mode->vsync_start - mode->vdisplay;
- timing->lower_margin = mode->vsync_start - mode->vdisplay; timing->vsync_len = mode->vsync_end - mode->vsync_start;
- timing->lower_margin = mode->vtotal - mode->vsync_end;
timing->upper_margin = mode->vtotal - mode->vsync_end;
if (mode->flags& DRM_MODE_FLAG_INTERLACE) timing->vmode = FB_VMODE_INTERLACED;
Hi Joonyoung,
On Thursday 08 March 2012 22:05:50 Joonyoung Shim wrote:
On 03/08/2012 08:34 PM, Laurent Pinchart wrote:
The fb_videomode structure stores the front porch and back porch in the right_margin and left_margin fields respectively. right_margin should thus be computed with hsync_start - hdisplay, and left_margin with htotal - hsync_end. The same holds for the vertical direction.
Active Front Sync Back Region Porch Porch<-------------------><----------------><-------------><---------------->
//////////////////|
////////////////// |
////////////////// |.................. ..................
_______________<------ xres -------><- right_margin -><- hsync_len -><- left_margin -->
<---- hdisplay -----> <------------ hsync_start ------------> <--------------------- hsync_end --------------------> <--------------------------------- htotal ----------------------------->
Fix the fb_videomode<-> drm_mode_modeinfo conversion functions accordingly.
Signed-off-by: Laurent Pinchartlaurent.pinchart@ideasonboard.com
drivers/gpu/drm/exynos/exynos_drm_connector.c | 16 ++++++++-------- 1 files changed, 8 insertions(+), 8 deletions(-)
While trying to understand how the fb_videomode and drm_mode_modeinfo fields map to each other, I found what might be a bug in the Exynos DRM driver. Could you please check and confirm that my understanding is correct ?
Good catch. You can refer Documentation/fb/framebuffer.txt to know in detail.
Acked-by: Joonyoung Shim jy0922.shim@samsung.com
Thank you. There's a similar issue in exynos_mipi_dsi_set_display_mode() where front and back porch are inverted. I'll submit a patch for that as well.
On Thu, Mar 08, 2012 at 04:31:51PM +0100, Laurent Pinchart wrote:
Hi Joonyoung,
On Thursday 08 March 2012 22:05:50 Joonyoung Shim wrote:
On 03/08/2012 08:34 PM, Laurent Pinchart wrote:
The fb_videomode structure stores the front porch and back porch in the right_margin and left_margin fields respectively. right_margin should thus be computed with hsync_start - hdisplay, and left_margin with htotal - hsync_end. The same holds for the vertical direction.
Active Front Sync Back Region Porch Porch<-------------------><----------------><-------------><---------------->
//////////////////|
////////////////// |
////////////////// |.................. ..................
_______________<------ xres -------><- right_margin -><- hsync_len -><- left_margin -->
<---- hdisplay -----> <------------ hsync_start ------------> <--------------------- hsync_end --------------------> <--------------------------------- htotal ----------------------------->
Fix the fb_videomode<-> drm_mode_modeinfo conversion functions accordingly.
Signed-off-by: Laurent Pinchartlaurent.pinchart@ideasonboard.com
drivers/gpu/drm/exynos/exynos_drm_connector.c | 16 ++++++++-------- 1 files changed, 8 insertions(+), 8 deletions(-)
While trying to understand how the fb_videomode and drm_mode_modeinfo fields map to each other, I found what might be a bug in the Exynos DRM driver. Could you please check and confirm that my understanding is correct ?
Good catch. You can refer Documentation/fb/framebuffer.txt to know in detail.
Acked-by: Joonyoung Shim jy0922.shim@samsung.com
Thank you. There's a similar issue in exynos_mipi_dsi_set_display_mode() where front and back porch are inverted. I'll submit a patch for that as well.
Damned. This seems to be a common misunderstanding. I never really thought about it and always assumed that 'front porch' and 'back porch' refers to the picture and not to the sync signal. I was so sure that I didn't even care to google it before I saw this patch.
Sascha
Hi Laurent,
-----Original Message----- From: Joonyoung Shim [mailto:jy0922.shim@samsung.com] Sent: Thursday, March 08, 2012 10:06 PM To: Laurent Pinchart Cc: dri-devel@lists.freedesktop.org; linux-fbdev@vger.kernel.org; Inki
Dae;
Seung-Woo Kim; Kyungmin Park Subject: Re: [PATCH] drm: exynos: Fix fb_videomode <-> drm_mode_modeinfo conversion
On 03/08/2012 08:34 PM, Laurent Pinchart wrote:
The fb_videomode structure stores the front porch and back porch in the right_margin and left_margin fields respectively. right_margin should thus be computed with hsync_start - hdisplay, and left_margin with htotal - hsync_end. The same holds for the vertical direction.
Active Front Sync Back Region Porch Porch<-------------------><----------------><-------------><---------------->
//////////////////| ////////////////// | ////////////////// |.................. .................. _______________
<------ xres -------><- right_margin -><- hsync_len -><- left_margin -->
<---- hdisplay -----> <------------ hsync_start ------------> <--------------------- hsync_end --------------------> <--------------------------------- htotal ----------------------------->
Fix the fb_videomode<-> drm_mode_modeinfo conversion functions accordingly.
Signed-off-by: Laurent Pinchartlaurent.pinchart@ideasonboard.com
drivers/gpu/drm/exynos/exynos_drm_connector.c | 16 ++++++++-------- 1 files changed, 8 insertions(+), 8 deletions(-)
While trying to understand how the fb_videomode and drm_mode_modeinfo
fields
map to each other, I found what might be a bug in the Exynos DRM driver.
Could
you please check and confirm that my understanding is correct ?
Good catch. You can refer Documentation/fb/framebuffer.txt to know in detail.
Acked-by: Joonyoung Shim jy0922.shim@samsung.com
Thanks.
it seems like that you doesn't use latest exynos drm driver so I merged it manually for this, you can refer to this link: http://git.infradead.org/users/kmpark/linux-samsung/shortlog/refs/heads/exyn os-drm-fixes
Thanks, Inki Dae
diff --git a/drivers/gpu/drm/exynos/exynos_drm_connector.c
b/drivers/gpu/drm/exynos/exynos_drm_connector.c
index d620b07..7bb1dca 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_connector.c +++ b/drivers/gpu/drm/exynos/exynos_drm_connector.c @@ -52,14 +52,14 @@ convert_to_display_mode(struct drm_display_mode
*mode,
mode->vrefresh = timing->refresh;
mode->hdisplay = timing->xres;
- mode->hsync_start = mode->hdisplay + timing->left_margin;
- mode->hsync_start = mode->hdisplay + timing->right_margin; mode->hsync_end = mode->hsync_start + timing->hsync_len;
- mode->htotal = mode->hsync_end + timing->right_margin;
mode->htotal = mode->hsync_end + timing->left_margin;
mode->vdisplay = timing->yres;
- mode->vsync_start = mode->vdisplay + timing->upper_margin;
- mode->vsync_start = mode->vdisplay + timing->lower_margin; mode->vsync_end = mode->vsync_start + timing->vsync_len;
- mode->vtotal = mode->vsync_end + timing->lower_margin;
mode->vtotal = mode->vsync_end + timing->upper_margin;
if (timing->vmode& FB_VMODE_INTERLACED) mode->flags |= DRM_MODE_FLAG_INTERLACE;
@@ -81,14 +81,14 @@ convert_to_video_timing(struct fb_videomode *timing, timing->refresh = drm_mode_vrefresh(mode);
timing->xres = mode->hdisplay;
- timing->left_margin = mode->hsync_start - mode->hdisplay;
- timing->right_margin = mode->hsync_start - mode->hdisplay; timing->hsync_len = mode->hsync_end - mode->hsync_start;
- timing->right_margin = mode->htotal - mode->hsync_end;
timing->left_margin = mode->htotal - mode->hsync_end;
timing->yres = mode->vdisplay;
- timing->upper_margin = mode->vsync_start - mode->vdisplay;
- timing->lower_margin = mode->vsync_start - mode->vdisplay; timing->vsync_len = mode->vsync_end - mode->vsync_start;
- timing->lower_margin = mode->vtotal - mode->vsync_end;
timing->upper_margin = mode->vtotal - mode->vsync_end;
if (mode->flags& DRM_MODE_FLAG_INTERLACE) timing->vmode = FB_VMODE_INTERLACED;
The fb_videomode structure stores the front porch and back porch in the right_margin and left_margin fields respectively. right_margin should thus be computed with hsync_start - hdisplay, and left_margin with htotal - hsync_end. The same holds for the vertical direction.
Active Front Sync Back Region Porch Porch<-------------------><----------------><-------------><---------------->
//////////////////| ////////////////// | ////////////////// |.................. .................. _______________
<------ xres -------><- right_margin -><- hsync_len -><- left_margin -->
<---- hdisplay -----> <------------ hsync_start ------------> <--------------------- hsync_end --------------------> <--------------------------------- htotal ----------------------------->
Fix the fb_videomode <-> drm_mode_modeinfo conversion functions accordingly.
Wow I see this has remegered. Some time last year I posted a patch that had these routines in a generic format for people to use. I can repost them again if people are interested.
On Fri, Mar 9, 2012 at 12:57 AM, James Simmons jsimmons@infradead.org wrote:
Wow I see this has remegered. Some time last year I posted a patch that had these routines in a generic format for people to use. I can repost them again if people are interested.
Yes please!
Hi James,
On Thursday 08 March 2012 16:57:21 James Simmons wrote:
The fb_videomode structure stores the front porch and back porch in the right_margin and left_margin fields respectively. right_margin should thus be computed with hsync_start - hdisplay, and left_margin with htotal - hsync_end. The same holds for the vertical direction.
Active Front Sync Back Region Porch Porch<-------------------><----------------><-------------><---------------->
//////////////////|
////////////////// |
////////////////// |.................. ..................
_______________<------ xres -------><- right_margin -><- hsync_len -><- left_margin -->
<---- hdisplay -----> <------------ hsync_start ------------> <--------------------- hsync_end --------------------> <--------------------------------- htotal ----------------------------->
Fix the fb_videomode <-> drm_mode_modeinfo conversion functions accordingly.
Wow I see this has remegered. Some time last year I posted a patch that had these routines in a generic format for people to use. I can repost them again if people are interested.
As part of the EDID parser rework, I will introduce a common structure to describe video modes. Conversion functions between the common structures and struct drm_mode_modeinfo, struct fb_videomode and struct v4l2_bt_timings will be provided. Direct conversion between drm_mode_modeinfo and fb_videomode should then disappear.
This being said, we could introduce add you conversion functions in the meantime. I will then post a patch to remove them when the common video mode structure will be pushed to mainline :-)
dri-devel@lists.freedesktop.org
-
Corbin Simpson -
Inki Dae -
James Simmons -
Joonyoung Shim -
Laurent Pinchart -
Sascha Hauer