Re: [PATCH 1/4] video: add fb_edid_add_monspecs for parsing
From: Andrew Morton <akpm@linux-foundation.org>
Date: 2010-10-28 23:17:19
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On Thu, 28 Oct 2010 14:34:44 +0200 (CEST) Guennadi Liakhovetski [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: Erik Gilling <redacted> Modern monitors/tvs have more extended EDID information blocks which can contain extra detailed modes. This adds a fb_edid_add_monspecs function which drivers can use to parse those additions blocks. Signed-off-by: Erik Gilling <redacted> --- drivers/video/fbmon.c | 57 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/fb.h | 2 + 2 files changed, 59 insertions(+), 0 deletions(-)diff --git a/drivers/video/fbmon.c b/drivers/video/fbmon.c index 563a98b..a0b5a93 100644 --- a/drivers/video/fbmon.c +++ b/drivers/video/fbmon.c@@ -973,6 +973,63 @@ void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs) DPRINTK("====================\n"); } +void fb_edid_add_monspecs(unsigned char *edid, struct fb_monspecs *specs)
Please document it. This is a general rule when implementing library-style functions.
+{
+ unsigned char *block;
+ struct fb_videomode *mode, *m;
+ int num = 0, i, first = 1;
+
+ if (edid = NULL)
+ return;
+
+ if (!edid_checksum(edid))
+ return;
+
+ if (edid[0] != 0x2)
+ return;
+
+ mode = kzalloc(50 * sizeof(struct fb_videomode), GFP_KERNEL);
+ if (mode = NULL)
+ return;
+
+ block = edid + edid[0x2];
+
+ DPRINTK(" Extended Detailed Timings\n");
+
+ for (i = 0; i < (128 - edid[0x2]) / DETAILED_TIMING_DESCRIPTION_SIZE;It should validate edid[2] first, methinks. If it's some crazy value then this loop will run off into the weeds.
+ i++, block += DETAILED_TIMING_DESCRIPTION_SIZE) {
+ if (!(block[0] = 0x00 && block[1] = 0x00)) {
+ get_detailed_timing(block, &mode[num]);
+ if (first) {
+ mode[num].flag |= FB_MODE_IS_FIRST;
+ first = 0;
+ }
+ num++;
+ }
+ }
+
+ /* Yikes, EDID data is totally useless */
+ if (!num) {
+ kfree(mode);
+ return;
+ }
+
+ m = kzalloc((specs->modedb_len + num) *
+ sizeof(struct fb_videomode), GFP_KERNEL);
+
+ if (!m) {
+ kfree(mode);
+ return;
+ }
+
+ memmove(m, specs->modedb, specs->modedb_len * sizeof(struct fb_videomode));
+ memmove(m + specs->modedb_len, mode, num * sizeof(struct fb_videomode));It's unusual to use memmove() for a copy which cannot overlap - memcpy() would be more typical. memmove() works though.
+ kfree(mode); + kfree(specs->modedb); + specs->modedb = m; + specs->modedb_len = specs->modedb_len + num; +}
Without an EXPORT_SYMBOL(), other modules cannot use this function?
quoted hunk ↗ jump to hunk
/* * VESA Generalized Timing Formula (GTF) */diff --git a/include/linux/fb.h b/include/linux/fb.h index f0268de..3fc99cb 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h@@ -1086,6 +1086,8 @@ extern int fb_parse_edid(unsigned char *edid, struct fb_var_screeninfo *var); extern const unsigned char *fb_firmware_edid(struct device *device); extern void fb_edid_to_monspecs(unsigned char *edid, struct fb_monspecs *specs); +extern void fb_edid_add_monspecs(unsigned char *edid, + struct fb_monspecs *specs); extern void fb_destroy_modedb(struct fb_videomode *modedb); extern int fb_find_mode_cvt(struct fb_videomode *mode, int margins, int rb); extern unsigned char *fb_ddc_read(struct i2c_adapter *adapter);-- 1.7.1