From: Thomas Reim <rdrat...@yahoo.co.uk>
Some integrated ATI Radeon chipset implementations
(e. g. Asus M2A-VM HDMI, RS690) indicate the availability
of a DDC even when there's no monitor connected.
In this case, drm_get_edid() and drm_edid_block_valid()
periodically dump data and kernel errors into system
log files and onto terminals, which lead to an unacceptable
system behaviour. For this purpose function drm_edid_header_is_valid()
has been added to drm and function drm_edid_block_valid()
has been adapted to also use drm_edid_header_is_valid().
Tested since kernel 2.35 on Asus M2A-VM HDMI board
Signed-off-by: Thomas Reim <rdratlos at yahoo.co.uk>
---
drivers/gpu/drm/drm_edid.c | 23 +++++++++++---
drivers/gpu/drm/radeon/radeon_connectors.c | 29 ++++++++++++++++-
drivers/gpu/drm/radeon/radeon_display.c | 12 +++++++
drivers/gpu/drm/radeon/radeon_i2c.c | 45 ++++++++++++++++++++++++++-
drivers/gpu/drm/radeon/radeon_mode.h | 4 ++
include/drm/drm_crtc.h | 1 +
6 files changed, 105 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 0929219..1daaf81 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -128,6 +128,23 @@ static const u8 edid_header[] = {
};
/*
+ * Sanity check the header of the base EDID block. Return 8 if the header
+ * is perfect, down to 0 if it's totally wrong.
+ */
+int drm_edid_header_is_valid(const u8 *raw_edid)
+{
+ int i, score = 0;
+
+ for (i = 0; i < sizeof(edid_header); i++)
+ if (raw_edid[i] == edid_header[i])
+ score++;
+
+ return score;
+}
+EXPORT_SYMBOL(drm_edid_header_is_valid);
+
+
+/*
* Sanity check the EDID block (base or extension). Return 0 if the block
* doesn't check out, or 1 if it's valid.
*/
@@ -139,11 +156,7 @@ drm_edid_block_valid(u8 *raw_edid)
struct edid *edid = (struct edid *)raw_edid;
if (raw_edid[0] == 0x00) {
- int score = 0;
-
- for (i = 0; i < sizeof(edid_header); i++)
- if (raw_edid[i] == edid_header[i])
- score++;
+ int score = drm_edid_header_is_valid(raw_edid);
if (score == 8) ;
else if (score >= 6) {
diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c
b/drivers/gpu/drm/radeon/radeon_connectors.c
index cbfca3a..bcd2380 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -826,8 +826,12 @@ radeon_dvi_detect(struct drm_connector *connector, bool
force)
enum drm_connector_status ret = connector_status_disconnected;
bool dret = false;
- if (radeon_connector->ddc_bus)
- dret = radeon_ddc_probe(radeon_connector);
+ if (radeon_connector->ddc_bus) {
+ if (radeon_connector->requires_extended_probe)
+ dret = radeon_ddc_probe_extended(radeon_connector);
+ else
+ dret = radeon_ddc_probe(radeon_connector);
+ }
if (dret) {
if (radeon_connector->edid) {
kfree(radeon_connector->edid);
@@ -1342,6 +1346,7 @@ radeon_add_atom_connector(struct drm_device *dev,
struct radeon_encoder *radeon_encoder;
uint32_t subpixel_order = SubPixelNone;
bool shared_ddc = false;
+ bool requires_extended_probe = false;
bool is_dp_bridge = false;
if (connector_type == DRM_MODE_CONNECTOR_Unknown)
@@ -1400,6 +1405,7 @@ radeon_add_atom_connector(struct drm_device *dev,
radeon_connector->shared_ddc = shared_ddc;
radeon_connector->connector_object_id = connector_object_id;
radeon_connector->hpd = *hpd;
+ radeon_connector->requires_extended_probe = requires_extended_probe;
radeon_connector->router = *router;
if (router->ddc_valid || router->cd_valid) {
radeon_connector->router_bus = radeon_i2c_lookup(rdev,
&router->i2c_info);
@@ -1688,6 +1694,23 @@ radeon_add_atom_connector(struct drm_device *dev,
}
}
+ /* RS690 HDMI DDC quirk:
+ * Some integrated ATI Radeon chipset implementations (e. g.
+ * Asus M2A-VM HDMI) indicate the availability of a DDC even
+ * when there's no monitor connected to HDMI. For HDMI
+ * connectors we check for the availability of EDID with
+ * at least a correct EDID header and EDID version/revision
+ * information. Only then, DDC is assumed to be available.
+ * This prevents drm_get_edid() and drm_edid_block_valid() of
+ * periodically dumping data and kernel errors into the logs
+ * and onto the terminal, which would lead to an unacceptable
+ * system behaviour */
+ if (connector_type == DRM_MODE_CONNECTOR_HDMIA &&
+ (rdev->family == CHIP_RS690 ||
+ rdev->family == CHIP_RS740 ||
+ rdev->family == CHIP_RV630))
+ requires_extended_probe = true;
+ radeon_connector->requires_extended_probe = requires_extended_probe;
if (radeon_connector->hpd.hpd == RADEON_HPD_NONE) {
if (i2c_bus->valid)
connector->polled = DRM_CONNECTOR_POLL_CONNECT;
@@ -1716,6 +1739,7 @@ radeon_add_legacy_connector(struct drm_device *dev,
struct drm_connector *connector;
struct radeon_connector *radeon_connector;
uint32_t subpixel_order = SubPixelNone;
+ bool requires_extended_probe = false;
if (connector_type == DRM_MODE_CONNECTOR_Unknown)
return;
@@ -1746,6 +1770,7 @@ radeon_add_legacy_connector(struct drm_device *dev,
radeon_connector->devices = supported_device;
radeon_connector->connector_object_id = connector_object_id;
radeon_connector->hpd = *hpd;
+ radeon_connector->requires_extended_probe = requires_extended_probe;
switch (connector_type) {
case DRM_MODE_CONNECTOR_VGA:
drm_connector_init(dev, &radeon_connector->base,
&radeon_vga_connector_funcs, connector_type);
diff --git a/drivers/gpu/drm/radeon/radeon_display.c
b/drivers/gpu/drm/radeon/radeon_display.c
index 292f73f..27e6840 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -715,6 +715,9 @@ static bool radeon_setup_enc_conn(struct drm_device *dev)
if (ret) {
radeon_setup_encoder_clones(dev);
radeon_print_display_setup(dev);
+ /* Is this really required here?
+ Seems to just force drm to dump EDID errors
+ to kernel logs */
list_for_each_entry(drm_connector,
&dev->mode_config.connector_list, head)
radeon_ddc_dump(drm_connector);
}
@@ -777,8 +780,17 @@ static int radeon_ddc_dump(struct drm_connector *connector)
if (!radeon_connector->ddc_bus)
return -1;
edid = drm_get_edid(connector, &radeon_connector->ddc_bus->adapter);
+ /* Log EDID retrieval status here. In particular with regard to
+ * connectors with requires_extended_probe flag set, that will prevent
+ * function radeon_dvi_detect() to fetch EDID on this connector,
+ * as long as there is no valid EDID header found */
if (edid) {
+ DRM_INFO("Radeon display connector %s: Found valid EDID",
+ drm_get_connector_name(connector));
kfree(edid);
+ } else {
+ DRM_INFO("Radeon display connector %s: No monitor connected or
invalid EDID",
+ drm_get_connector_name(connector));
}
return ret;
}
diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c
b/drivers/gpu/drm/radeon/radeon_i2c.c
index 781196d..7e93cf9 100644
--- a/drivers/gpu/drm/radeon/radeon_i2c.c
+++ b/drivers/gpu/drm/radeon/radeon_i2c.c
@@ -34,7 +34,7 @@
*/
bool radeon_ddc_probe(struct radeon_connector *radeon_connector)
{
- u8 out_buf[] = { 0x0, 0x0};
+ u8 out = 0x0;
u8 buf[2];
int ret;
struct i2c_msg msgs[] = {
@@ -42,7 +42,7 @@ bool radeon_ddc_probe(struct radeon_connector
*radeon_connector)
.addr = 0x50,
.flags = 0,
.len = 1,
- .buf = out_buf,
+ .buf = &out,
},
{
.addr = 0x50,
@@ -63,6 +63,47 @@ bool radeon_ddc_probe(struct radeon_connector
*radeon_connector)
return false;
}
+/*
+ * Probe EDID header information via I2C:
+ * Try to fetch EDID information by calling i2c_transfer driver function and
+ * probe for a valid EDID header
+ */
+bool radeon_ddc_probe_extended(struct radeon_connector *radeon_connector)
+{
+ u8 out = 0x0;
+ u8 block[8];
+ int ret;
+ struct i2c_msg msgs[] = {
+ {
+ .addr = 0x50,
+ .flags = 0,
+ .len = 1,
+ .buf = &out,
+ }, {
+ .addr = 0x50,
+ .flags = I2C_M_RD,
+ .len = 8,
+ .buf = block,
+ }
+ };
+
+ /* on hw with routers, select right port */
+ if (radeon_connector->router.ddc_valid)
+ radeon_router_select_ddc_port(radeon_connector);
+
+ ret = i2c_transfer(&radeon_connector->ddc_bus->adapter, msgs, 2);
+ if (ret == 2)
+ if (drm_edid_header_is_valid(block) >= 6)
+ /* EDID header starts with:
+ * 0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x00
+ * Only the first 6 bytes must be valid as
+ * drm_edid_block_valid() can fix the last 2 bytes
+ */
+ return true;
+ /* Couldn't find an accessible EDID on this connector */
+ return false;
+}
+
/* bit banging i2c */
static void radeon_i2c_do_lock(struct radeon_i2c_chan *i2c, int lock_state)
diff --git a/drivers/gpu/drm/radeon/radeon_mode.h
b/drivers/gpu/drm/radeon/radeon_mode.h
index 6df4e3c..b834f27 100644
--- a/drivers/gpu/drm/radeon/radeon_mode.h
+++ b/drivers/gpu/drm/radeon/radeon_mode.h
@@ -438,6 +438,9 @@ struct radeon_connector {
struct radeon_i2c_chan *ddc_bus;
/* some systems have an hdmi and vga port with a shared ddc line */
bool shared_ddc;
+ /* for some Radeon chip families we apply an additional EDID header
+ check as part of the DDC probe */
+ bool requires_extended_probe;
bool use_digital;
/* we need to mind the EDID between detect
and get modes due to analog/digital/tvencoder */
@@ -515,6 +518,7 @@ extern void radeon_i2c_put_byte(struct radeon_i2c_chan *i2c,
extern void radeon_router_select_ddc_port(struct radeon_connector
*radeon_connector);
extern void radeon_router_select_cd_port(struct radeon_connector
*radeon_connector);
extern bool radeon_ddc_probe(struct radeon_connector *radeon_connector);
+extern bool radeon_ddc_probe_extended(struct radeon_connector
*radeon_connector);
extern int radeon_ddc_get_modes(struct radeon_connector *radeon_connector);
extern struct drm_encoder *radeon_best_encoder(struct drm_connector
*connector);
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 33d12f8..0ec3687 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -802,6 +802,7 @@ extern struct drm_display_mode *drm_gtf_mode_complex(struct
drm_device *dev,
extern int drm_add_modes_noedid(struct drm_connector *connector,
int hdisplay, int vdisplay);
+extern int drm_edid_header_is_valid(const u8 *raw_edid);
extern bool drm_edid_is_valid(struct edid *edid);
struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev,
int hsize, int vsize, int fresh);
--
1.7.1
