0958944a93
The MT9P006 sensor driver sporadically fails to probe because the sensor responds with a NACK condition to I2C address on the bus during an attempt to read the sensor MT9P031_CHIP_VERSION register in mt9p031_registered(). Neither the MT9P006 nor MT9P031 datasheets are clear on reset signal timing. Older MT9M034 [1] datasheet provides those timing figures in Appendix-A and indicates it is necessary to wait 850000 EXTCLK cycles before starting any I2C communication. Add such a delay, which does make the sporadic I2C NACK go away, so it is likely similar constraint applies to this sensor. [1] https://www.onsemi.com/pdf/datasheet/mt9m034-d.pdf Signed-off-by: Marek Vasut <marex@denx.de> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.