On 2019-11-01 22:01, Will Deacon wrote:
On Fri, Sep 20, 2019 at 01:34:26PM +0530, Sai Prakash Ranjan wrote:
Previous version of the patches are at [1]:
QCOM's implementation of smmu-500 on sdm845 adds a hardware logic
called
wait-for-safe. This logic helps in meeting the invalidation
requirements
from 'real-time clients', such as display and camera. This
wait-for-safe
logic ensures that the invalidations happen after getting an ack from
these
devices.
In this patch-series we are disabling this wait-for-safe logic from
the
arm-smmu driver's probe as with this enabled the hardware tries to
throttle invalidations from 'non-real-time clients', such as USB and
UFS.
For detailed information please refer to patch [3/4] in this series.
I have included the device tree patch too in this series for someone
who
would like to test out this. Here's a branch [2] that gets display on
MTP
SDM845 device.
This patch series is inspired from downstream work to handle
under-performance
issues on real-time clients on sdm845. In downstream we add separate
page table
ops to handle TLB maintenance and toggle wait-for-safe in tlb_sync
call so that
achieve required performance for display and camera [3, 4].
What's the plan for getting this merged? I'm not happy taking the
firmware
bits without Andy's ack, but I also think the SMMU changes should go
via
the IOMMU tree to avoid conflicts.
Andy?
Bjorn maintains QCOM stuff now if I am not wrong and he has already
reviewed the firmware bits. So I'm hoping you could take all these
through IOMMU tree.
-Sai
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