This is a note to let you know that I've just added the patch titled

drm/i915: Don't try indexed reads to alternate slave addresses

to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: drm-i915-don-t-try-indexed-reads-to-alternate-slave-addresses.patch and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From ae5c631e605a452a5a0e73205a92810c01ed954b Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= ville.syrjala@linux.intel.com Date: Thu, 23 Nov 2017 21:41:56 +0200 Subject: drm/i915: Don't try indexed reads to alternate slave addresses MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

From: Ville Syrjälä ville.syrjala@linux.intel.com

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.s... 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

--- drivers/gpu/drm/i915/intel_i2c.c | 1 + 1 file changed, 1 insertion(+)

--- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -394,6 +394,7 @@ 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)); }

Patches currently in stable-queue which might be from ville.syrjala@linux.intel.com are

queue-3.18/drm-i915-prevent-zero-length-index-write.patch queue-3.18/drm-i915-don-t-try-indexed-reads-to-alternate-slave-addresses.patch