This patch is ported from linux stable 4.9, commit 3587c856675c45809010c2cee5b21096f6e8e938.
So I think I don't need to port on version 4.9.
On 9/8/2017 2:21 PM, Greg KH wrote:
On Fri, Sep 08, 2017 at 09:46:02AM +0700, Nhan Nguyen wrote:
commit 3587c856675c45809010c2cee5b21096f6e8e938 upstream.
I've found that by just turning the chip on and off via the
POWER_DOWN register, I end up getting i2c_transfer errors on
HiKey.
Investigating further, it turns out that some of the register
state in hardware is getting lost, as the device registers are
reset when the chip is powered down.
Thus this patch simply re-writes the i2c address to the
ADV7511_REG_EDID_I2C_ADDR register to ensure its properly set
before we try to read the EDID data.
Cc: David Airlie <airlied@xxxxxxxx>
Cc: Archit Taneja <architt@xxxxxxxxxxxxxx>
Cc: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
Cc: Lars-Peter Clausen <lars@xxxxxxxxxx>
Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Tested-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
Signed-off-by: Archit Taneja <architt@xxxxxxxxxxxxxx>
Signed-off-by: Thong Ho <thong.ho.px@xxxxxxxxxxxxxxx>
Signed-off-by: Nhan Nguyen <nhan.nguyen.yb@xxxxxxxxxxx>
Link: http://patchwork.freedesktop.org/patch/msgid/1484614372-15342-7-git-send-email-john.stultz@xxxxxxxxxx
---
drivers/gpu/drm/i2c/adv7511.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
Can you provide a working backport for the 4.9-stable kernel as well?
Also, please do not send backports for patches that do not also work in
newer stable kernels, like 4.9, I backported some of this series there,
but I shouldn't have to check for you.
thanks,
greg k-h