[PATCH] video: msmfb: Put the partial update magic value into the fix_screen struct.

[PATCH] video: msmfb: Put the partial update magic value into the fix_screen struct.

[Carl Vanderlip]

From: Dima Zavin <dima@android.com>

This can then be tested by userspace to see if the capability is supported.
Userspace cannot rely on that value being left in var_screen, since userspace
itself can change it.

---
 drivers/video/msm/msm_fb.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/drivers/video/msm/msm_fb.c b/drivers/video/msm/msm_fb.c
index 5436aeb..bbf841e 100644
--- a/drivers/video/msm/msm_fb.c
+++ b/drivers/video/msm/msm_fb.c
@@ -469,6 +469,14 @@ static void setup_fb_info(struct msmfb_info *msmfb)
 	fb_info->var.yoffset = 0;
 
 	if (msmfb->panel->caps & MSMFB_CAP_PARTIAL_UPDATES) {
+		/* set the param in the fixed screen, so userspace can't
+		 * change it. This will be used to check for the
+		 * capability. */
+		fb_info->fix.reserved[0] = 0x5444;
+		fb_info->fix.reserved[1] = 0x5055;
+
+		/* This preloads the value so that if userspace doesn't
+		 * change it, it will be a full update */
 		fb_info->var.reserved[0] = 0x54445055;
 		fb_info->var.reserved[1] = 0;
 		fb_info->var.reserved[2] = (uint16_t)msmfb->xres |
-- 
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

RE: [PATCH] video: msmfb: Put the partial update magic value into the fix_screen struct.

[Janorkar, Mayuresh]

> -----Original Message-----
> From: linux-fbdev-owner@vger.kernel.org [mailto:linux-fbdev-
> owner@vger.kernel.org] On Behalf Of Carl Vanderlip
> Sent: Saturday, February 26, 2011 2:36 AM
> To: davidb@codeaurora.org
> Cc: Dima Zavin; open list:ARM/QUALCOMM MSM...; open list:FRAMEBUFFER
> LAYER; open list
> Subject: [PATCH] video: msmfb: Put the partial update magic value into the
> fix_screen struct.
> 
> From: Dima Zavin <dima@android.com>
> 
> This can then be tested by userspace to see if the capability is
> supported.
> Userspace cannot rely on that value being left in var_screen, since
> userspace
> itself can change it.
> 
Missing Signed-off-by:
checkpatch would give error for this.
> ---
>  drivers/video/msm/msm_fb.c |    8 ++++++++
>  1 files changed, 8 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/video/msm/msm_fb.c b/drivers/video/msm/msm_fb.c
> index 5436aeb..bbf841e 100644
> --- a/drivers/video/msm/msm_fb.c
> +++ b/drivers/video/msm/msm_fb.c
> @@ -469,6 +469,14 @@ static void setup_fb_info(struct msmfb_info *msmfb)
>  	fb_info->var.yoffset = 0;
> 
>  	if (msmfb->panel->caps & MSMFB_CAP_PARTIAL_UPDATES) {
> +		/* set the param in the fixed screen, so userspace can't
> +		 * change it. This will be used to check for the
> +		 * capability. */
Multi-line comments?
> +		fb_info->fix.reserved[0] = 0x5444;
> +		fb_info->fix.reserved[1] = 0x5055;
> +
> +		/* This preloads the value so that if userspace doesn't
> +		 * change it, it will be a full update */
Multi-line comments?
>  		fb_info->var.reserved[0] = 0x54445055;
>  		fb_info->var.reserved[1] = 0;
>  		fb_info->var.reserved[2] = (uint16_t)msmfb->xres |
> --
> Sent by an employee of the Qualcomm Innovation Center, Inc.
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
> 
> --
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