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87c2c27165
Adding a new CSIPHY init sequence using downstream as a reference prompted me to look at why we are splitting up the init sequence into chunks. Right now we declare CSI PHY init sequences as an array of five equally sized writes with a hard-coded control loop to iterate through each of the five indexes. One bug in this model is that if you don't have an even number of writes, you can't init the PHY as you wish. In downstream the original code has something of the character phy_init_seq[MAX_LANES][MAX_PARAMS] which in upstream we have translated into phy_init_seq[5][SOME_NUMBER_OF_EQUAL_WRITES]; What the code does is take a pointer to the first index of the r = &phy_init_seq[0][0]; and then literally does write(r, value); r++; The controlling loop that hard-codes '5' in-lieu of MAX_LANES does no special sleep, fabric-coherence sync or even a printk() to justify its existence. Our compilers are optimising all of this away anyway so lets drop. Reduce the array declaration down to one flat aggregate init and let the code just step through. As a happy side-effect we can then also handle odd-number writes as the number of elements in the init sequence will no longer have to be evenly divisible. Reviewed-by: Elliot Berman <quic_eberman@quicinc.com> Reviewed-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> Signed-off-by: Depeng Shao <quic_depengs@quicinc.com> Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> |
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| fs | ||
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| init | ||
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| ipc | ||
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| lib | ||
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| .cocciconfig | ||
| .editorconfig | ||
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| README | ||
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 reStructuredText 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.