diff options
| author | Alex Deucher <alexander.deucher@amd.com> | 2015-02-20 11:51:38 -0500 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2015-02-25 16:06:10 -0500 |
| commit | 94a47c49fe5dc0c4d1e56bc1286623df3ea53b23 (patch) | |
| tree | cab942bf28b7a4e3b1fe5b6f98e1ff2abb485fba /drivers/gpu/drm/radeon | |
| parent | dbfb00c3e7e18439f2ebf67fe99bf7a50b5bae1e (diff) | |
drm/radeon: fix atom aux payload size check for writes (v2)
The atom aux param interface only supports 4 bits for
the total write transfer size (header + payload). This
limits us to 12 bytes of payload rather than 16. Add a
check for this. Reads are not affected.
v2: switch to WARN_ON_ONCE
Reviewed-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/radeon')
| -rw-r--r-- | drivers/gpu/drm/radeon/atombios_dp.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c index 5bf825dfaa09..8d74de82456e 100644 --- a/drivers/gpu/drm/radeon/atombios_dp.c +++ b/drivers/gpu/drm/radeon/atombios_dp.c @@ -178,6 +178,13 @@ radeon_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) switch (msg->request & ~DP_AUX_I2C_MOT) { case DP_AUX_NATIVE_WRITE: case DP_AUX_I2C_WRITE: + /* The atom implementation only supports writes with a max payload of + * 12 bytes since it uses 4 bits for the total count (header + payload) + * in the parameter space. The atom interface supports 16 byte + * payloads for reads. The hw itself supports up to 16 bytes of payload. + */ + if (WARN_ON_ONCE(msg->size > 12)) + return -E2BIG; /* tx_size needs to be 4 even for bare address packets since the atom * table needs the info in tx_buf[3]. */ |