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authorVille Syrjälä <ville.syrjala@linux.intel.com>2017-11-23 21:41:56 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-12-05 11:24:35 +0100
commit838cdb26a538aa83326639f53ce4f8112f23dd96 (patch)
parentdaf3a68d52826e697eb20c1f290aa198d43dfad5 (diff)
drm/i915: Don't try indexed reads to alternate slave addresses
commit ae5c631e605a452a5a0e73205a92810c01ed954b upstream. We can only specify the one slave address to indexed reads/writes. Make sure the messages we check are destined to the same slave address before deciding to do an indexed transfer. Cc: Daniel Kurtz <djkurtz@chromium.org> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Sean Paul <seanpaul@chromium.org> Fixes: 56f9eac05489 ("drm/i915/intel_i2c: use INDEX cycles for i2c read transactions") Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20171123194157.25367-2-ville.syrjala@linux.intel.com Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (cherry picked from commit c4deb62d7821672265b87952bcd1c808f3bf3e8f) Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
index 79aab9ad6faa..f8b406b88c77 100644
--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ b/drivers/gpu/drm/i915/intel_i2c.c
@@ -430,6 +430,7 @@ static bool
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 + 1].flags & I2C_M_RD));