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path: root/drivers/gpu/drm/drm_edid.c
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Diffstat (limited to 'drivers/gpu/drm/drm_edid.c')
-rw-r--r--drivers/gpu/drm/drm_edid.c153
1 files changed, 103 insertions, 50 deletions
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 805fb004c8eb..ec10dc3e859c 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -1590,11 +1590,22 @@ static int validate_displayid(u8 *displayid, int length, int idx);
static int drm_edid_block_checksum(const u8 *raw_edid)
{
int i;
- u8 csum = 0;
- for (i = 0; i < EDID_LENGTH; i++)
+ u8 csum = 0, crc = 0;
+
+ for (i = 0; i < EDID_LENGTH - 1; i++)
csum += raw_edid[i];
- return csum;
+ crc = 0x100 - csum;
+
+ return crc;
+}
+
+static bool drm_edid_block_checksum_diff(const u8 *raw_edid, u8 real_checksum)
+{
+ if (raw_edid[EDID_LENGTH - 1] != real_checksum)
+ return true;
+ else
+ return false;
}
static bool drm_edid_is_zero(const u8 *in_edid, int length)
@@ -1652,7 +1663,7 @@ bool drm_edid_block_valid(u8 *raw_edid, int block, bool print_bad_edid,
}
csum = drm_edid_block_checksum(raw_edid);
- if (csum) {
+ if (drm_edid_block_checksum_diff(raw_edid, csum)) {
if (edid_corrupt)
*edid_corrupt = true;
@@ -1793,6 +1804,11 @@ static void connector_bad_edid(struct drm_connector *connector,
u8 *edid, int num_blocks)
{
int i;
+ u8 num_of_ext = edid[0x7e];
+
+ /* Calculate real checksum for the last edid extension block data */
+ connector->real_edid_checksum =
+ drm_edid_block_checksum(edid + num_of_ext * EDID_LENGTH);
if (connector->bad_edid_counter++ && !drm_debug_enabled(DRM_UT_KMS))
return;
@@ -2196,15 +2212,29 @@ struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
}
EXPORT_SYMBOL(drm_mode_find_dmt);
+static bool is_display_descriptor(const u8 d[18], u8 tag)
+{
+ return d[0] == 0x00 && d[1] == 0x00 &&
+ d[2] == 0x00 && d[3] == tag;
+}
+
+static bool is_detailed_timing_descriptor(const u8 d[18])
+{
+ return d[0] != 0x00 || d[1] != 0x00;
+}
+
typedef void detailed_cb(struct detailed_timing *timing, void *closure);
static void
cea_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure)
{
- int i, n = 0;
+ int i, n;
u8 d = ext[0x02];
u8 *det_base = ext + d;
+ if (d < 4 || d > 127)
+ return;
+
n = (127 - d) / 18;
for (i = 0; i < n; i++)
cb((struct detailed_timing *)(det_base + 18 * i), closure);
@@ -2254,9 +2284,12 @@ static void
is_rb(struct detailed_timing *t, void *data)
{
u8 *r = (u8 *)t;
- if (r[3] == EDID_DETAIL_MONITOR_RANGE)
- if (r[15] & 0x10)
- *(bool *)data = true;
+
+ if (!is_display_descriptor(r, EDID_DETAIL_MONITOR_RANGE))
+ return;
+
+ if (r[15] & 0x10)
+ *(bool *)data = true;
}
/* EDID 1.4 defines this explicitly. For EDID 1.3, we guess, badly. */
@@ -2276,7 +2309,11 @@ static void
find_gtf2(struct detailed_timing *t, void *data)
{
u8 *r = (u8 *)t;
- if (r[3] == EDID_DETAIL_MONITOR_RANGE && r[10] == 0x02)
+
+ if (!is_display_descriptor(r, EDID_DETAIL_MONITOR_RANGE))
+ return;
+
+ if (r[10] == 0x02)
*(u8 **)data = r;
}
@@ -2815,13 +2852,13 @@ do_inferred_modes(struct detailed_timing *timing, void *c)
struct detailed_non_pixel *data = &timing->data.other_data;
struct detailed_data_monitor_range *range = &data->data.range;
- if (data->type != EDID_DETAIL_MONITOR_RANGE)
+ if (!is_display_descriptor((const u8 *)timing, EDID_DETAIL_MONITOR_RANGE))
return;
closure->modes += drm_dmt_modes_for_range(closure->connector,
closure->edid,
timing);
-
+
if (!version_greater(closure->edid, 1, 1))
return; /* GTF not defined yet */
@@ -2894,10 +2931,11 @@ static void
do_established_modes(struct detailed_timing *timing, void *c)
{
struct detailed_mode_closure *closure = c;
- struct detailed_non_pixel *data = &timing->data.other_data;
- if (data->type == EDID_DETAIL_EST_TIMINGS)
- closure->modes += drm_est3_modes(closure->connector, timing);
+ if (!is_display_descriptor((const u8 *)timing, EDID_DETAIL_EST_TIMINGS))
+ return;
+
+ closure->modes += drm_est3_modes(closure->connector, timing);
}
/**
@@ -2946,19 +2984,19 @@ do_standard_modes(struct detailed_timing *timing, void *c)
struct detailed_non_pixel *data = &timing->data.other_data;
struct drm_connector *connector = closure->connector;
struct edid *edid = closure->edid;
+ int i;
- if (data->type == EDID_DETAIL_STD_MODES) {
- int i;
- for (i = 0; i < 6; i++) {
- struct std_timing *std;
- struct drm_display_mode *newmode;
+ if (!is_display_descriptor((const u8 *)timing, EDID_DETAIL_STD_MODES))
+ return;
- std = &data->data.timings[i];
- newmode = drm_mode_std(connector, edid, std);
- if (newmode) {
- drm_mode_probed_add(connector, newmode);
- closure->modes++;
- }
+ for (i = 0; i < 6; i++) {
+ struct std_timing *std = &data->data.timings[i];
+ struct drm_display_mode *newmode;
+
+ newmode = drm_mode_std(connector, edid, std);
+ if (newmode) {
+ drm_mode_probed_add(connector, newmode);
+ closure->modes++;
}
}
}
@@ -3053,15 +3091,16 @@ static void
do_cvt_mode(struct detailed_timing *timing, void *c)
{
struct detailed_mode_closure *closure = c;
- struct detailed_non_pixel *data = &timing->data.other_data;
- if (data->type == EDID_DETAIL_CVT_3BYTE)
- closure->modes += drm_cvt_modes(closure->connector, timing);
+ if (!is_display_descriptor((const u8 *)timing, EDID_DETAIL_CVT_3BYTE))
+ return;
+
+ closure->modes += drm_cvt_modes(closure->connector, timing);
}
static int
add_cvt_modes(struct drm_connector *connector, struct edid *edid)
-{
+{
struct detailed_mode_closure closure = {
.connector = connector,
.edid = edid,
@@ -3083,27 +3122,28 @@ do_detailed_mode(struct detailed_timing *timing, void *c)
struct detailed_mode_closure *closure = c;
struct drm_display_mode *newmode;
- if (timing->pixel_clock) {
- newmode = drm_mode_detailed(closure->connector->dev,
- closure->edid, timing,
- closure->quirks);
- if (!newmode)
- return;
+ if (!is_detailed_timing_descriptor((const u8 *)timing))
+ return;
- if (closure->preferred)
- newmode->type |= DRM_MODE_TYPE_PREFERRED;
+ newmode = drm_mode_detailed(closure->connector->dev,
+ closure->edid, timing,
+ closure->quirks);
+ if (!newmode)
+ return;
- /*
- * Detailed modes are limited to 10kHz pixel clock resolution,
- * so fix up anything that looks like CEA/HDMI mode, but the clock
- * is just slightly off.
- */
- fixup_detailed_cea_mode_clock(newmode);
+ if (closure->preferred)
+ newmode->type |= DRM_MODE_TYPE_PREFERRED;
- drm_mode_probed_add(closure->connector, newmode);
- closure->modes++;
- closure->preferred = false;
- }
+ /*
+ * Detailed modes are limited to 10kHz pixel clock resolution,
+ * so fix up anything that looks like CEA/HDMI mode, but the clock
+ * is just slightly off.
+ */
+ fixup_detailed_cea_mode_clock(newmode);
+
+ drm_mode_probed_add(closure->connector, newmode);
+ closure->modes++;
+ closure->preferred = false;
}
/*
@@ -3953,6 +3993,13 @@ cea_db_tag(const u8 *db)
static int
cea_revision(const u8 *cea)
{
+ /*
+ * FIXME is this correct for the DispID variant?
+ * The DispID spec doesn't really specify whether
+ * this is the revision of the CEA extension or
+ * the DispID CEA data block. And the only value
+ * given as an example is 0.
+ */
return cea[1];
}
@@ -3977,6 +4024,10 @@ cea_db_offsets(const u8 *cea, int *start, int *end)
* no non-DTD data.
*/
if (cea[0] == DATA_BLOCK_CTA) {
+ /*
+ * for_each_displayid_db() has already verified
+ * that these stay within expected bounds.
+ */
*start = 3;
*end = *start + cea[2];
} else if (cea[0] == CEA_EXT) {
@@ -4282,8 +4333,10 @@ drm_parse_hdmi_vsdb_audio(struct drm_connector *connector, const u8 *db)
static void
monitor_name(struct detailed_timing *t, void *data)
{
- if (t->data.other_data.type == EDID_DETAIL_MONITOR_NAME)
- *(u8 **)data = t->data.other_data.data.str.str;
+ if (!is_display_descriptor((const u8 *)t, EDID_DETAIL_MONITOR_NAME))
+ return;
+
+ *(u8 **)data = t->data.other_data.data.str.str;
}
static int get_monitor_name(struct edid *edid, char name[13])
@@ -4316,7 +4369,7 @@ void drm_edid_get_monitor_name(struct edid *edid, char *name, int bufsize)
{
int name_length;
char buf[13];
-
+
if (bufsize <= 0)
return;
generated by cgit v1.2.3 (git 2.25.1) at 2025-04-11 21:20:56 +0000