edc0596cc0
Commit aa53f580e67b ("scsi: ufs: Minor adjustments to error handling")
introduced a ufshcd_clear_ua_wluns() call in
ufshcd_err_handling_unprepare(). As explained in detail by Adrian Hunter,
this can trigger a deadlock. Avoid that deadlock by removing the code that
clears the unit attention. This is safe because the only software that
relies on clearing unit attentions is the Android Trusty software and
because support for handling unit attentions has been added in the Trusty
software.
See also https://lore.kernel.org/linux-scsi/20210930124224.114031-2-adrian.hunter@intel.com/
Note that "scsi: ufs: Retry START_STOP on UNIT_ATTENTION" is a prerequisite
for this commit.
Link: https://lore.kernel.org/r/20211001182015.1347587-3-jaegeuk@kernel.org
Fixes: aa53f580e67b ("scsi: ufs: Minor adjustments to error handling")
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Bart Van Assche <bvanassche@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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.