[PATCH v2 0/3] drm: fix i2c adapter device driver user counter

[Vladimir Zapolskiy]

David, Russell,

ping.

On 23.09.2015 00:46, Vladimir Zapolskiy wrote:
> of_find_i2c_adapter_by_node() call requires quite often missing
> put_device(), and i2c_put_adapter() releases a device locked by
> i2c_get_adapter() only.
> 
> Below is a common error reproduction scenario as a result of the
> misusage described above (this is run on iMX6 platform with
> HDMI and I2C bus drivers compiled as kernel modules for clearness):
> 
>     root at mx6q:~# lsmod | grep i2c
>     i2c_imx                15348  0
>     root at mx6q:~# lsmod | grep dw_hdmi_imx
>     dw_hdmi_imx             3567  0
>     dw_hdmi                15850  1 dw_hdmi_imx
>     imxdrm                  8610  3 dw_hdmi_imx,imx_ipuv3_crtc,imx_ldb
>     root at mx6q:~# rmmod dw_hdmi_imx
>     root at mx6q:~# lsmod | grep i2c
>     i2c_imx                15348  -1
> 
>                                  ^^^^^
> 
>     root at mx6q:~# rmmod i2c_imx
>     rmmod: ERROR: Module i2c_imx is in use
> 
> To fix existing users of these interfaces use of_get_i2c_adapter_by_node()
> interface, which is similar to i2c_get_adapter() in sense that an I2C bus
> device driver found and locked by a user can be correctly unlocked by
> i2c_put_adapter() call.
> 
> Changes from v1 to v2:
> - none, this series is a straightforward bugfix, v1 was a blend of
>   I2C core changes, bugfixes and improvements
> 
> The change is based on dri/drm-next.
> 
> Vladimir Zapolskiy (3):
>   drm: dw_hdmi: use of_get_i2c_adapter_by_node interface
>   drm: tilcdc: use of_get_i2c_adapter_by_node interface
>   drm: tegra: use of_get_i2c_adapter_by_node interface
> 
>  drivers/gpu/drm/bridge/dw_hdmi.c       | 14 +++++++++-----
>  drivers/gpu/drm/tegra/output.c         | 23 ++++++++++++-----------
>  drivers/gpu/drm/tilcdc/tilcdc_tfp410.c |  6 ++----
>  3 files changed, 23 insertions(+), 20 deletions(-)
> 

--
With best wishes,
Vladimir