Alexey Sheplyakov
6e55d27370
On a dual core group GPUs (such as T628) fragment shading can be performed over all cores (because a fragment shader job doesn't need coherency between threads), however vertex shading requires to be run on the same core group as the tiler (which always lives in core group 0). As a first step to support T628 power on only the first core group (so no jobs are scheduled on the second one). This makes T628 look like every other Midgard GPU (and throws away up to half the cores). With this patch panfrost is able to drive T628 (r1p0) GPU on some armv8 SoCs (in particular BE-M1000). Without the patch rendering is horribly broken (desktop is completely unusable) and eventually the GPU locks up (it takes from a few seconds to a couple of minutes). Using the second core group requires support in Mesa (and an UABI change): the userspace should 1) set PANFROST_JD_DOESNT_NEED_COHERENCY_ON_GPU flag to opt-in to allowing the job to run across all cores. 2) set PANFROST_RUN_ON_SECOND_CORE_GROUP flag to allow compute jobs to be run on the second core group (at the moment Mesa does not advertise compute support on anything older than Mali T760) But there's little point adding such flags until someone (myself) steps up to do the Mesa work. Signed-off-by: Alexey Sheplyakov <asheplyakov@basealt.ru> Signed-off-by: Vadim V. Vlasov <vadim.vlasov@elpitech.ru> Tested-by: Alexey Sheplyakov <asheplyakov@basealt.ru> Co-developed-by: Steven Price <steven.price@arm.com> Signed-off-by: Steven Price <steven.price@arm.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220115160658.582646-1-asheplyakov@basealt.ru
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.