From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Tobias Schandinat Date: Thu, 01 Sep 2011 13:10:28 +0000 Subject: Re: [PATCH] fbdev: fix parsing of standard timings Message-Id: <4E5F8444.4010503@gmx.de> List-Id: References: <1314362328-30456-1-git-send-email-tomi.valkeinen@ti.com> In-Reply-To: <1314362328-30456-1-git-send-email-tomi.valkeinen@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-fbdev@vger.kernel.org On 08/30/2011 05:31 AM, Tomi Valkeinen wrote: > Hi Florian, > > On Fri, 2011-08-26 at 18:02 +0000, Florian Tobias Schandinat wrote: >> Hi Tomi, >> >> On 08/26/2011 12:38 PM, Tomi Valkeinen wrote: >>> The standard timings parses uses 1:1 dimensions when the ratio in the >>> EDID data is 0. However, for EDID 1.3 and later the dimensions are 16:10 >>> when the ratio is 0. >>> >>> Pass the version and revision numbers to get_std_timing() which can then >>> make the right decision about dimensions. >>> >>> Signed-off-by: Tomi Valkeinen >> >> Thanks, looks good to me. >> I'd be happy if someone with access to the original EDID specs could confirm >> this and add his reviewed by. >> I also think adding a comment explaining this change would be helpful. > > You can see the same thing done in > drivers/gpu/drm/drm_edid.c:drm_mode_std(). Although they seem to check > only revision, which looks a bit risky to me. > > The specs seem to be available by just googling them, although I don't > know if it's legal to distribute them or not... > > I've added your comment, I agree it's good. Patch below. Looks like your googling is better than mine, I only found references to it. Anyway, I've applied this patch. Thanks, Florian Tobias Schandinat > > Tomi > > >>>From 82c630291ad39d45009352fce1b23b4d0f44f92d Mon Sep 17 00:00:00 2001 > From: Tomi Valkeinen > Date: Thu, 25 Aug 2011 15:36:40 +0300 > Subject: [PATCH] fbdev: fix parsing of standard timings > > The standard timings parses uses 1:1 dimensions when the ratio in the > EDID data is 0. However, for EDID 1.3 and later the dimensions are 16:10 > when the ratio is 0. > > Pass the version and revision numbers to get_std_timing() which can then > make the right decision about dimensions. > > Signed-off-by: Tomi Valkeinen > --- > drivers/video/fbmon.c | 21 +++++++++++++++------ > 1 files changed, 15 insertions(+), 6 deletions(-) > > diff --git a/drivers/video/fbmon.c b/drivers/video/fbmon.c > index 4f57485..cef6557 100644 > --- a/drivers/video/fbmon.c > +++ b/drivers/video/fbmon.c > @@ -493,7 +493,8 @@ static int get_est_timing(unsigned char *block, struct fb_videomode *mode) > return num; > } > > -static int get_std_timing(unsigned char *block, struct fb_videomode *mode) > +static int get_std_timing(unsigned char *block, struct fb_videomode *mode, > + int ver, int rev) > { > int xres, yres = 0, refresh, ratio, i; > > @@ -504,7 +505,11 @@ static int get_std_timing(unsigned char *block, struct fb_videomode *mode) > ratio = (block[1] & 0xc0) >> 6; > switch (ratio) { > case 0: > - yres = xres; > + /* in EDID 1.3 the meaning of 0 changed to 16:10 (prior 1:1) */ > + if (ver < 1 || (ver = 1 && rev < 3)) > + yres = xres; > + else > + yres = (xres * 10)/16; > break; > case 1: > yres = (xres * 3)/4; > @@ -533,12 +538,12 @@ static int get_std_timing(unsigned char *block, struct fb_videomode *mode) > } > > static int get_dst_timing(unsigned char *block, > - struct fb_videomode *mode) > + struct fb_videomode *mode, int ver, int rev) > { > int j, num = 0; > > for (j = 0; j < 6; j++, block += STD_TIMING_DESCRIPTION_SIZE) > - num += get_std_timing(block, &mode[num]); > + num += get_std_timing(block, &mode[num], ver, rev); > > return num; > } > @@ -599,6 +604,10 @@ static struct fb_videomode *fb_create_modedb(unsigned char *edid, int *dbsize) > struct fb_videomode *mode, *m; > unsigned char *block; > int num = 0, i, first = 1; > + int ver, rev; > + > + ver = edid[EDID_STRUCT_VERSION]; > + rev = edid[EDID_STRUCT_REVISION]; > > mode = kzalloc(50 * sizeof(struct fb_videomode), GFP_KERNEL); > if (mode = NULL) > @@ -632,12 +641,12 @@ static struct fb_videomode *fb_create_modedb(unsigned char *edid, int *dbsize) > DPRINTK(" Standard Timings\n"); > block = edid + STD_TIMING_DESCRIPTIONS_START; > for (i = 0; i < STD_TIMING; i++, block += STD_TIMING_DESCRIPTION_SIZE) > - num += get_std_timing(block, &mode[num]); > + num += get_std_timing(block, &mode[num], ver, rev); > > block = edid + DETAILED_TIMING_DESCRIPTIONS_START; > for (i = 0; i < 4; i++, block+= DETAILED_TIMING_DESCRIPTION_SIZE) { > if (block[0] = 0x00 && block[1] = 0x00 && block[3] = 0xfa) > - num += get_dst_timing(block + 5, &mode[num]); > + num += get_dst_timing(block + 5, &mode[num], ver, rev); > } > > /* Yikes, EDID data is totally useless */