diff options
| author | Ville Syrjälä <[email protected]> | 2017-11-23 21:41:57 +0200 |
|---|---|---|
| committer | Joonas Lahtinen <[email protected]> | 2017-11-28 10:31:42 +0200 |
| commit | 56350fb8978bbf4aafe08f21234e161dd128b417 (patch) | |
| tree | a320fd79bf0af4ebcc115e6f980a00474a55b3a0 | |
| parent | ae5c631e605a452a5a0e73205a92810c01ed954b (diff) | |
drm/i915: Prevent zero length "index" write
The hardware always writes one or two bytes in the index portion of
an indexed transfer. Make sure the message we send as the index
doesn't have a zero length.
Cc: [email protected]
Cc: Daniel Kurtz <[email protected]>
Cc: Chris Wilson <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Sean Paul <[email protected]>
Fixes: 56f9eac05489 ("drm/i915/intel_i2c: use INDEX cycles for i2c read transactions")
Signed-off-by: Ville Syrjälä <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Reviewed-by: Chris Wilson <[email protected]>
(cherry picked from commit bb9e0d4bca50f429152e74a459160b41f3d60fb2)
Signed-off-by: Joonas Lahtinen <[email protected]>
| -rw-r--r-- | drivers/gpu/drm/i915/intel_i2c.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index 8affd47b98b8..49fdf09f9919 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -439,7 +439,8 @@ gmbus_is_index_read(struct i2c_msg *msgs, int i, int num) { return (i + 1 < num && msgs[i].addr == msgs[i + 1].addr && - !(msgs[i].flags & I2C_M_RD) && msgs[i].len <= 2 && + !(msgs[i].flags & I2C_M_RD) && + (msgs[i].len == 1 || msgs[i].len == 2) && (msgs[i + 1].flags & I2C_M_RD)); } |