Hi Greg, On Saturday, March 30, 2019 6:47:12 AM CET Greg KH wrote: > On Fri, Mar 29, 2019 at 10:20:05PM +0100, Janusz Krzysztofik wrote: > > After removal of clock_start() from before soc_camera_init_i2c() in > > soc_camera_probe() by commit 9aea470b399d ("[media] soc-camera: switch > > I2C subdevice drivers to use v4l2-clk") introduced in v3.11, the ov6650 > > driver could no longer probe the sensor successfully because its clock > > was no longer turned on in advance. The issue was initially worked > > around by adding that missing clock_start() equivalent to OMAP1 camera > > interface driver - the only user of this sensor - but a propoer fix > > should be rather implemented in the sensor driver code itself. > > > > Fix the issue by inserting a delay between the clock is turned on and > > the sensor I2C registers are read for the first time. > > > > Fixes: 9aea470b399d ("[media] soc-camera: switch I2C subdevice drivers to use v4l2-clk") > > Signed-off-by: Janusz Krzysztofik <jmkrzyszt@xxxxxxxxx> > > Cc: stable@xxxxxxxxxxxxxxx > > --- > > Rebased on 3.18, should apply cleanly on 4.4 and 4.9 as well. > > > > I dropped the comment on the patch being tested on an out of tree > > omap1_camera driver mainly because that driver is still in the tree > > in those kernel versions. > > > > drivers/media/i2c/soc_camera/ov6650.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/media/i2c/soc_camera/ov6650.c b/drivers/media/i2c/ soc_camera/ov6650.c > > index ab01598ec83f..c0e25bf55fb8 100644 > > --- a/drivers/media/i2c/soc_camera/ov6650.c > > +++ b/drivers/media/i2c/soc_camera/ov6650.c > > @@ -829,6 +829,8 @@ static int ov6650_video_probe(struct i2c_client *client) > > if (ret < 0) > > return ret; > > > > + msleep(20); > > + > > /* > > * check and show product ID and manufacturer ID > > */ > > What is the git commit id of this patch in Linus's tree? Not yet in Linus' tree, but already applied by Sakari Ailus in his https://git.linuxtv.org/sailus/media_tree.git/, id=cea17210dc0ee140289d900144662e70ea8aa623. FYI, I submitted this backport in order to address the following request from the following automated off-list response to my original submission (https://www.spinics.net/lists/stable/msg293064.html). > [This is an automated email] > > This commit has been processed because it contains a "Fixes:" tag, > fixing commit: 9aea470b399d [media] soc-camera: switch I2C subdevice drivers to use v4l2-clk. > > The bot has tested the following trees: v5.0.4, v4.19.31, v4.14.108, v4.9.165, v4.4.177, v3.18.137. > > v5.0.4: Build OK! > v4.19.31: Build OK! > v4.14.108: Build OK! > v4.9.165: Failed to apply! Possible dependencies: > Unable to calculate > > v4.4.177: Failed to apply! Possible dependencies: > Unable to calculate > > v3.18.137: Failed to apply! Possible dependencies: > Unable to calculate > > > How should we proceed with this patch? The reason was the driver moved into a different directory in 4.14. Inspired by your request, I've just learned how such info on original commit should be included in the commit message. I can resend with that added as soon as the patch lands in Linus' tree if you wish. Thanks, Janusz