The 01/10 change adds and exports new of_get_i2c_adapter_by_node()
interface of i2c core, the rest of patches fix current users of
of_find_i2c_adapter_by_node() interface.
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. In general module_put(adapter->owner) and
put_device(dev) are not interchangeable.
This 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@mx6q:~# lsmod | grep i2c
i2c_imx 10213 0
root@mx6q:~# lsmod | grep dw_hdmi_imx
dw_hdmi_imx 3631 0
dw_hdmi 11846 1 dw_hdmi_imx
imxdrm 8674 3 dw_hdmi_imx,imx_ipuv3_crtc,imx_ldb
drm_kms_helper 113765 5 dw_hdmi,imxdrm,imx_ipuv3_crtc,imx_ldb
root@mx6q:~# rmmod dw_hdmi_imx
root@mx6q:~# lsmod | grep i2c
i2c_imx 10213 -1
^^^^^
root@mx6q:~# rmmod i2c_imx
rmmod: ERROR: Module i2c_imx is in use
To fix existing users of these interfaces and to avoid any further
confusion and misusage in future, add one more interface
of_get_i2c_adapter_by_node(), it is similar to i2c_get_adapter() in
sense that an I2C bus device driver found and locked by user can be
correctly unlocked by i2c_put_adapter().
Mainly the change concerns DRM users of I2C bus device.
The change is based on torvalds/master branch, d6ac4ffc61a
RFC of the 01/10 change is http://www.spinics.net/lists/linux-i2c/msg20257.html
Vladimir Zapolskiy (10):
i2c: add and export of_get_i2c_adapter_by_node() interface
drm: dw_hdmi: use of_get_i2c_adapter_by_node interface
drm: exynos_hdmi: use of_get_i2c_adapter_by_node interface
drm: imx-tve: use of_get_i2c_adapter_by_node interface
drm: panel-simple: use of_get_i2c_adapter_by_node interface
drm: sti_hdmi: use of_get_i2c_adapter_by_node interface
drm: tegra: use of_get_i2c_adapter_by_node interface
drm: tilcdc: use of_get_i2c_adapter_by_node interface
fbdev: omap2: connector-dvi: use of_get_i2c_adapter_by_node interface
i2c: i2c-arb-gpio-challenge: use of_get_i2c_adapter_by_node interface
drivers/gpu/drm/bridge/dw_hdmi.c | 14 ++++--
drivers/gpu/drm/exynos/exynos_hdmi.c | 7 +--
drivers/gpu/drm/imx/imx-tve.c | 56 +++++++++++++++-------
drivers/gpu/drm/panel/panel-simple.c | 9 ++--
drivers/gpu/drm/sti/sti_hdmi.c | 19 +++-----
drivers/gpu/drm/tegra/output.c | 19 ++++----
drivers/gpu/drm/tilcdc/tilcdc_tfp410.c | 6 +--
drivers/i2c/i2c-core.c | 20 ++++++++
drivers/i2c/muxes/i2c-arb-gpio-challenge.c | 3 +-
.../video/fbdev/omap2/displays-new/connector-dvi.c | 2 +-
include/linux/i2c.h | 6 +++
11 files changed, 104 insertions(+), 57 deletions(-)
--
2.1.4
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