Writes to CURSURFLIVE in TGL are causing IOMMU errors and visual glitches that are often reproduced when executing CPU intensive workloads while a eDP 4K panel is attached. Manually exiting PSR causes the frontbuffer to be updated without glitches and the IOMMU errors are also gone but this comes at the cost of less time with PSR active. So using this workaround until this issue is root caused and a better fix is found. The current code is already ready to enable PSR after this exit if there is not other frontbuffer modifications. Adding a new if block in psr_force_hw_tracking_exit() instead of reuse the else/gen8- block because the plan is to revert this workaround as soon as a better solution is found. Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: José Roberto de Souza <jose.souza@intel.com> Tested-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com> Reviewed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201002231627.24528-1-jose.souza@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.
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