4d2391a0dd
hsw/bdw lack the pipe register vs. display register distinction in their PSR masking capabilities. So to keep our CURSURFLIVE tricks working we need to just unmask all display register writes on these platforms. The downside being that any display regitster (eg. even SWF regs) will cause a PSR exit. Note that WaMaskMMIOWriteForPSR asks us to mask this on bdw, but that won't work since we need those CURSURFLIVE tricks. Observations on actual hardware show that this causes one extra PSR exit ~every 10 seconds, which is pretty much irrelevant. I suspect this is due to the pcode poking at IPS_CTL. Disabling IPS does not stop it however, so either I'm wrong or pcode pokes at the register regardless of whether it's actually trying to enable/disable IPS. Also when the machine is busy (eg. just running 'find /') these extra PSR exits cease, which again points at pcode or some other PM entity as being the culprit. Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20230609141404.12729-11-ville.syrjala@linux.intel.com Reviewed-by: Jouni Högander <jouni.hogander@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.