Re: [PATCH 13/21] arc: dma-mapping: skip invalidating before bidirectional DMA

Shahab Vahedi
2023-04-06T09:09:04Z

On 4/2/23 08:52, Vineet Gupta wrote:
> CC Shahab
>
> On 3/27/23 17:43, Arnd Bergmann wrote:
>> From: Arnd Bergmann<arnd@arndb.de>
>>
>> Some architectures that need to invalidate buffers after bidirectional
>> DMA because of speculative prefetching only do a simpler writeback
>> before that DMA, while architectures that don't need to do the second
>> invalidate tend to have a combined writeback+invalidate before the
>> DMA.
>>
>> arc is one of the architectures that does both, which seems unnecessary.
>>
>> Change it to behave like arm/arm64/xtensa instead, and use just a
>> writeback before the DMA when we do the invalidate afterwards.
>>
>> Signed-off-by: Arnd Bergmann<arnd@arndb.de>
>
> Reviewed-by: Vineet Gupta <vgupta@kernel.org>
>
> Shahab can you give this a spin on hsdk - run glibc testsuite over ssh
> and make sure nothing strange happens.
>
> Thx,
> -Vineet

Tested-by: Shahab Vahedi <shahab@synopsys.com>

No regression was observed for the ARC target before and after applying
these 21 patches. The test environment and its summary follow.

board: ARC HSDK
base: repo: linux-next
tag: next-20230403
commit: 31bd35b66249 Add linux-next specific files for 20230403
hotfix: net: stmmac: check fwnode for phy device before scanning for phy [1]
glibc: 2.37

Summary of test results:
20 FAIL
4227 PASS
38 UNSUPPORTED
16 XFAIL
2 XPASS

[1]
https://lore.kernel.org/lkml/20230405093945.3549491-1-michael.wei.hong.sit@intel.com/#r

--
Shahab