Field Firmware Update (ffu) may use close-ended or open ended sequence. Each such sequence is comprised of a write commands enclosed between 2 switch commands - to and from ffu mode. So for the close-ended case, it will be: cmd6->cmd23-cmd25-cmd6. Some host controllers however, get confused when multi-block rw is sent without sbc, and may generate auto-cmd12 which breaks the ffu sequence. I encountered this issue while testing fwupd (github.com/fwupd/fwupd) on HP Chromebook x2, a qualcomm based QC-7c, code name - strongbad. Instead of a quirk, or hooking the request function of the msm ops, it would be better to fix the ioctl handling and make it use mrq.sbc instead of issuing SET_BLOCK_COUNT separately. Signed-off-by: Avri Altman <avri.altman@wdc.com> Acked-by: Adrian Hunter <adrian.hunter@intel.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20231129092535.3278-1-avri.altman@wdc.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.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.
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