mx3fb: Fix parameter to sdc_init_panel

h_end_width and v_end_width should only contain the front porches.
Otherwise, SCREEN_WIDTH (pixel clocks between HSYNC) in SDC_HOR_CONF
and SCREEN_HEIGHT (rows between VSYNC) in SDC_VER_CONF get false values.

Signed-off-by: Alexander Stein <redacted>
---
 drivers/video/mx3fb.c |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/video/mx3fb.c b/drivers/video/mx3fb.c
index ef71e56..9040833 100644
--- a/drivers/video/mx3fb.c
+++ b/drivers/video/mx3fb.c

@@ -881,12 +881,11 @@ static int __set_par(struct fb_info *fbi, bool lock)
 				   IPU_PIX_FMT_BGR666 : IPU_PIX_FMT_RGB666,
 				   fbi->var.left_margin,
 				   fbi->var.hsync_len,
-				   fbi->var.right_margin +
-				   fbi->var.hsync_len,
+				   fbi->var.right_margin,
 				   fbi->var.upper_margin,
 				   fbi->var.vsync_len,
-				   fbi->var.lower_margin +
-				   fbi->var.vsync_len, sig_cfg) != 0) {
+				   fbi->var.lower_margin,
+				   sig_cfg) != 0) {
 			dev_err(fbi->device,
 				"mx3fb: Error initializing panel.\n");
 			return -EINVAL;

-- 
1.7.3.4

On Thu, 10 Feb 2011, Alexander Stein wrote:

h_end_width and v_end_width should only contain the front porches.
Otherwise, SCREEN_WIDTH (pixel clocks between HSYNC) in SDC_HOR_CONF
and SCREEN_HEIGHT (rows between VSYNC) in SDC_VER_CONF get false values.

Hm, no, this corrupts image on my pcm990 test-board. What makes you think 
this patch is needed? How do you see, that current values are "false?"

Thanks
Guennadi

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

On Thu, 10 Feb 2011, Guennadi Liakhovetski wrote:

On Thu, 10 Feb 2011, Alexander Stein wrote:

quoted

h_end_width and v_end_width should only contain the front porches.
Otherwise, SCREEN_WIDTH (pixel clocks between HSYNC) in SDC_HOR_CONF
and SCREEN_HEIGHT (rows between VSYNC) in SDC_VER_CONF get false values.

Hm, no, this corrupts image on my pcm990 test-board. What makes you think 
this patch is needed? How do you see, that current values are "false?"

Thanks
Guennadi

quoted

Signed-off-by: Alexander Stein <redacted>
---
 drivers/video/mx3fb.c |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/video/mx3fb.c b/drivers/video/mx3fb.c
index ef71e56..9040833 100644
--- a/drivers/video/mx3fb.c
+++ b/drivers/video/mx3fb.c

@@ -881,12 +881,11 @@ static int __set_par(struct fb_info *fbi, bool lock)

Also just occurred to me - your offset of 881 lines is 100 lines below my 
offset for the same code - against what tree is this patch, or do you have 
some local changes there? Can it be, that that's the reason for your 
problem?

Thanks
Guennadi

quoted

 				   IPU_PIX_FMT_BGR666 : IPU_PIX_FMT_RGB666,
 				   fbi->var.left_margin,
 				   fbi->var.hsync_len,
-				   fbi->var.right_margin +
-				   fbi->var.hsync_len,
+				   fbi->var.right_margin,
 				   fbi->var.upper_margin,
 				   fbi->var.vsync_len,
-				   fbi->var.lower_margin +
-				   fbi->var.vsync_len, sig_cfg) != 0) {
+				   fbi->var.lower_margin,
+				   sig_cfg) != 0) {
 			dev_err(fbi->device,
 				"mx3fb: Error initializing panel.\n");
 			return -EINVAL;
-- 
1.7.3.4

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

On Thursday 10 February 2011, 12:00:09 Guennadi Liakhovetski wrote:

On Thu, 10 Feb 2011, Guennadi Liakhovetski wrote:

quoted

On Thu, 10 Feb 2011, Alexander Stein wrote:

quoted

h_end_width and v_end_width should only contain the front porches.
Otherwise, SCREEN_WIDTH (pixel clocks between HSYNC) in SDC_HOR_CONF
and SCREEN_HEIGHT (rows between VSYNC) in SDC_VER_CONF get false
values.

Hm, no, this corrupts image on my pcm990 test-board. What makes you think
this patch is needed? How do you see, that current values are "false?"

Ok, i will just write about HSYNC the problem about VSYNC is similar.
Let's assume we have a display with the following properties.
left_margin   = 38
right_margin  = 32
hsync_len     = 20
width         = 800

Without the patch we get the following arguments on sdc_init_panel
width           = 800
h_start_width   = 38 (left_margin)
h_sync_width    = 20 (hsync_len)
h_end_width     = 52 = 32 + 20 (right_margin + hsync_len)

So we will write into SDC_HOR_CONF:

reg = ((h_sync_width - 1) << 26) |
    ((width + h_start_width + h_end_width - 1) << 16);
reg = ((20 - 1) << 26) |
    ((800 + 38 + 52 - 1) << 16);

So the value SCREEN_WIDTH get written is
width + left_margin + right_margin + hsync_len
which is IMO wrong. The description in the reference manual states:

Screen width minus 1. Specifies the number of pixel clock periods between
the last HSYNC and the new HSYNC.

It should just be: width + left_margin + right_margin
I fell accross it, as I have a display with 800 px width and rather big 
left_margin. The sum got greater than 1023 which is what SCREEN_WIDTH can hold 
at maximum.

I don't know which display you used, but I guess your right_margin (and 
lower_margin) needs to be adjusted.

quoted

quoted

Signed-off-by: Alexander Stein <redacted>
---

 drivers/video/mx3fb.c |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/video/mx3fb.c b/drivers/video/mx3fb.c
index ef71e56..9040833 100644
--- a/drivers/video/mx3fb.c
+++ b/drivers/video/mx3fb.c

@@ -881,12 +881,11 @@ static int __set_par(struct fb_info *fbi, bool

lock)

Also just occurred to me - your offset of 881 lines is 100 lines below my
offset for the same code - against what tree is this patch, or do you have
some local changes there? Can it be, that that's the reason for your
problem?

Oh, I didn't rebase this patch on current linux git. This patch is on my 
2.6.34 kernel. Anyway, since 2.6.34 there are no related patches on mx3fb.c.

Alexander

On Thu, 10 Feb 2011, Alexander Stein wrote:

On Thursday 10 February 2011, 12:00:09 Guennadi Liakhovetski wrote:

quoted

On Thu, 10 Feb 2011, Guennadi Liakhovetski wrote:

quoted

On Thu, 10 Feb 2011, Alexander Stein wrote:

quoted

h_end_width and v_end_width should only contain the front porches.
Otherwise, SCREEN_WIDTH (pixel clocks between HSYNC) in SDC_HOR_CONF
and SCREEN_HEIGHT (rows between VSYNC) in SDC_VER_CONF get false
values.

Hm, no, this corrupts image on my pcm990 test-board. What makes you think
this patch is needed? How do you see, that current values are "false?"

(I certainly meant the pcm037 module)

Ok, i will just write about HSYNC the problem about VSYNC is similar.
Let's assume we have a display with the following properties.
left_margin   = 38
right_margin  = 32
hsync_len     = 20
width         = 800

Without the patch we get the following arguments on sdc_init_panel
width           = 800
h_start_width   = 38 (left_margin)
h_sync_width    = 20 (hsync_len)
h_end_width     = 52 = 32 + 20 (right_margin + hsync_len)

So we will write into SDC_HOR_CONF:

reg = ((h_sync_width - 1) << 26) |
    ((width + h_start_width + h_end_width - 1) << 16);
reg = ((20 - 1) << 26) |
    ((800 + 38 + 52 - 1) << 16);

So the value SCREEN_WIDTH get written is
width + left_margin + right_margin + hsync_len
which is IMO wrong. The description in the reference manual states:

quoted

Screen width minus 1. Specifies the number of pixel clock periods between
the last HSYNC and the new HSYNC.

It should just be: width + left_margin + right_margin
I fell accross it, as I have a display with 800 px width and rather big 
left_margin. The sum got greater than 1023 which is what SCREEN_WIDTH can hold 
at maximum.

I don't know which display you used, but I guess your right_margin (and 
lower_margin) needs to be adjusted.

Ok, agree. But then you need to adjust all current users and have them 
tested... Otherwise, of course, you can just adjust your platform panel 
data to work with the current calculations, even though in principle your 
patch seems to be doing the right thing (tm), according to the manual. But 
if applied as is without fixing all the users, it can very well break 
them...

Thanks
Guennadi

quoted

quoted

quoted

Signed-off-by: Alexander Stein <redacted>
---

 drivers/video/mx3fb.c |    7 +++----
 1 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/video/mx3fb.c b/drivers/video/mx3fb.c
index ef71e56..9040833 100644
--- a/drivers/video/mx3fb.c
+++ b/drivers/video/mx3fb.c

@@ -881,12 +881,11 @@ static int __set_par(struct fb_info *fbi, bool

lock)

Also just occurred to me - your offset of 881 lines is 100 lines below my
offset for the same code - against what tree is this patch, or do you have
some local changes there? Can it be, that that's the reason for your
problem?

Oh, I didn't rebase this patch on current linux git. This patch is on my 
2.6.34 kernel. Anyway, since 2.6.34 there are no related patches on mx3fb.c.

Alexander

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

On Thursday 10 February 2011, 13:48:23 Guennadi Liakhovetski wrote:

quoted

Ok, i will just write about HSYNC the problem about VSYNC is similar.
Let's assume we have a display with the following properties.
left_margin   = 38
right_margin  = 32
hsync_len     = 20
width         = 800

Without the patch we get the following arguments on sdc_init_panel
width           = 800
h_start_width   = 38 (left_margin)
h_sync_width    = 20 (hsync_len)
h_end_width     = 52 = 32 + 20 (right_margin + hsync_len)

So we will write into SDC_HOR_CONF:

reg = ((h_sync_width - 1) << 26) |

    ((width + h_start_width + h_end_width - 1) << 16);

reg = ((20 - 1) << 26) |

    ((800 + 38 + 52 - 1) << 16);

So the value SCREEN_WIDTH get written is
width + left_margin + right_margin + hsync_len

which is IMO wrong. The description in the reference manual states:

quoted

Screen width minus 1. Specifies the number of pixel clock periods
between the last HSYNC and the new HSYNC.

It should just be: width + left_margin + right_margin
I fell accross it, as I have a display with 800 px width and rather big
left_margin. The sum got greater than 1023 which is what SCREEN_WIDTH can
hold at maximum.

I don't know which display you used, but I guess your right_margin (and
lower_margin) needs to be adjusted.

Ok, agree. But then you need to adjust all current users and have them
tested... Otherwise, of course, you can just adjust your platform panel

4 more quoted lines

Ok, I've just seen there are some model defines in mx3fb.c which would also be 
affected.
I'll try to find all mx3fb users and fix their videomodes and repost a new 
patch.

Alexander

On Thursday 10 February 2011, 14:01:17 Alexander Stein wrote:

On Thursday 10 February 2011, 13:48:23 Guennadi Liakhovetski wrote:

quoted

quoted

I don't know which display you used, but I guess your right_margin (and
lower_margin) needs to be adjusted.

Ok, agree. But then you need to adjust all current users and have them
tested... Otherwise, of course, you can just adjust your platform panel
data to work with the current calculations, even though in principle your
patch seems to be doing the right thing (tm), according to the manual.
But if applied as is without fixing all the users, it can very well
break them...

Ok, I've just seen there are some model defines in mx3fb.c which would also
be affected.
I'll try to find all mx3fb users and fix their videomodes and repost a new
patch.

Uh, this seems next to impossible for me to handle it my own. I checked some 
users of the mx3fb but I cant say which ones will be affected and which ones 
not (e.g. without any hsync/vsync, on data enable).
I've not idea how to fix it then.

Alexander

On Mon, 14 Feb 2011, Alexander Stein wrote:

On Thursday 10 February 2011, 14:01:17 Alexander Stein wrote:

quoted

On Thursday 10 February 2011, 13:48:23 Guennadi Liakhovetski wrote:

quoted

quoted

I don't know which display you used, but I guess your right_margin (and
lower_margin) needs to be adjusted.

Ok, agree. But then you need to adjust all current users and have them
tested... Otherwise, of course, you can just adjust your platform panel
data to work with the current calculations, even though in principle your
patch seems to be doing the right thing (tm), according to the manual.
But if applied as is without fixing all the users, it can very well
break them...

Ok, I've just seen there are some model defines in mx3fb.c which would also
be affected.
I'll try to find all mx3fb users and fix their videomodes and repost a new
patch.

Uh, this seems next to impossible for me to handle it my own. I checked some 
users of the mx3fb but I cant say which ones will be affected and which ones 
not (e.g. without any hsync/vsync, on data enable).
I've not idea how to fix it then.

Well, you can, of course, adjust parameters for your platform to be able 
to run with this incorrect parameter definition...

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

On Monday 14 February 2011, 08:57:04 Guennadi Liakhovetski wrote:

On Mon, 14 Feb 2011, Alexander Stein wrote:

quoted

On Thursday 10 February 2011, 14:01:17 Alexander Stein wrote:

quoted

On Thursday 10 February 2011, 13:48:23 Guennadi Liakhovetski wrote:

quoted

quoted

I don't know which display you used, but I guess your right_margin
(and lower_margin) needs to be adjusted.

Ok, agree. But then you need to adjust all current users and have
them tested... Otherwise, of course, you can just adjust your
platform panel data to work with the current calculations, even
though in principle your patch seems to be doing the right thing
(tm), according to the manual. But if applied as is without fixing
all the users, it can very well break them...

Ok, I've just seen there are some model defines in mx3fb.c which would
also be affected.
I'll try to find all mx3fb users and fix their videomodes and repost a
new patch.

Uh, this seems next to impossible for me to handle it my own. I checked
some users of the mx3fb but I cant say which ones will be affected and
which ones not (e.g. without any hsync/vsync, on data enable).
I've not idea how to fix it then.

Well, you can, of course, adjust parameters for your platform to be able
to run with this incorrect parameter definition...

This is just an ugly work-around. Depending on the settings you may even get 
an overflow resulting in a not-working display at all.

Alexander

On Mon, 14 Feb 2011, Alexander Stein wrote:

On Monday 14 February 2011, 08:57:04 Guennadi Liakhovetski wrote:

quoted

On Mon, 14 Feb 2011, Alexander Stein wrote:

quoted

On Thursday 10 February 2011, 14:01:17 Alexander Stein wrote:

quoted

On Thursday 10 February 2011, 13:48:23 Guennadi Liakhovetski wrote:

quoted

quoted

I don't know which display you used, but I guess your right_margin
(and lower_margin) needs to be adjusted.

Ok, agree. But then you need to adjust all current users and have
them tested... Otherwise, of course, you can just adjust your
platform panel data to work with the current calculations, even
though in principle your patch seems to be doing the right thing
(tm), according to the manual. But if applied as is without fixing
all the users, it can very well break them...

Ok, I've just seen there are some model defines in mx3fb.c which would
also be affected.
I'll try to find all mx3fb users and fix their videomodes and repost a
new patch.

Uh, this seems next to impossible for me to handle it my own. I checked
some users of the mx3fb but I cant say which ones will be affected and
which ones not (e.g. without any hsync/vsync, on data enable).
I've not idea how to fix it then.

Well, you can, of course, adjust parameters for your platform to be able
to run with this incorrect parameter definition...

This is just an ugly work-around. Depending on the settings you may even get 
an overflow resulting in a not-working display at all.

Sure, I know, that this is a work-around. But I don't see options apart 
from

1. fix the driver and maybe a couple of platforms, that we have at hand 
and hope, that others will fix theirs or shout loud enough, when they 
discover, that their platforms are broken

2. fix the driver and all users and try to get as many of them as we can 
to test our fixes

3. leave the driver and work around the bug in all new platforms

Choose your poison;)

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/