b279b53015
This workaround applies to graphics 20.04 on all engines. Workaround has three parts : 1. Pipe flush before MI_ATOMIC - This part isn't relevant to Xe (at least not right now) since we don't use MI_ATOMIC anywhere in the kernel mode driver. 2. Memory-based interrupt masking - Memory-based interrupt processing isn't supported on physical functions, only virtual functions, according to bspec 60352. So this is probably only relevant once SRIOV support lands in the driver. 3. Disabling CSB/timestamp updates to the ghwsp and pphwsp - Workaround is added by this change. The CSB reports to gHWSP and ppHWSP have been discussed as part of a different topic on some internal threads and we've confirmed that neither the KMD nor the GuC firmware use those for anything, so disabling them is always "safe" and should have no functional or performance impact on system operation. The same is true for the timestamp updates in the ppHWSP as well. Given that, it might make sense to just combine these two workarounds into a single record (and single patch) and apply it on all steppings. Disabling the reports for RCS on higher steppings doesn't have any kind of negative impact and will simplify the overall situation. V3(MattR): - Combine WA apply same WA for all engines, no performance impact V2(MattR): - Mention detail in commit message - Reorder bit define - Improve bit naming - Remove workaround part which isnt relevant Reviewed-by: Matt Roper <matthew.d.roper@intel.com> Signed-off-by: Tejas Upadhyay <tejas.upadhyay@intel.com> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.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.