diff options
Diffstat (limited to 'drivers/gpu/drm/radeon/radeon_i2c.c')
| -rw-r--r-- | drivers/gpu/drm/radeon/radeon_i2c.c | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c b/drivers/gpu/drm/radeon/radeon_i2c.c index 781196db792f..6c111c1fa3f9 100644 --- a/drivers/gpu/drm/radeon/radeon_i2c.c +++ b/drivers/gpu/drm/radeon/radeon_i2c.c @@ -32,17 +32,17 @@ * radeon_ddc_probe * */ -bool radeon_ddc_probe(struct radeon_connector *radeon_connector) +bool radeon_ddc_probe(struct radeon_connector *radeon_connector, bool requires_extended_probe) { - u8 out_buf[] = { 0x0, 0x0}; - u8 buf[2]; + u8 out = 0x0; + u8 buf[8]; int ret; struct i2c_msg msgs[] = { { .addr = 0x50, .flags = 0, .len = 1, - .buf = out_buf, + .buf = &out, }, { .addr = 0x50, @@ -52,15 +52,31 @@ bool radeon_ddc_probe(struct radeon_connector *radeon_connector) } }; + /* Read 8 bytes from i2c for extended probe of EDID header */ + if (requires_extended_probe) + msgs[1].len = 8; + /* 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) - return true; - - return false; + if (ret != 2) + /* Couldn't find an accessible DDC on this connector */ + return false; + if (requires_extended_probe) { + /* Probe also for valid EDID header + * 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 */ + if (drm_edid_header_is_valid(buf) < 6) { + /* Couldn't find an accessible EDID on this + * connector */ + return false; + } + } + return true; } /* bit banging i2c */ |