Re: [PATCH 0/2] spi: spi-qcom-qspi: Avoid some per-transfer overhead

[Rajendra Nayak]

On 7/8/2020 1:46 AM, Douglas Anderson wrote:
> Not to be confused with the similar series I posed for the _other_
> Qualcomm SPI controller (spi-geni-qcom) [1], this one avoids the
> overhead on the Quad SPI controller.
>
> It's based atop the current Qualcomm tree including Rajendra's ("spi:
> spi-qcom-qspi: Use OPP API to set clk/perf state").  As discussed in
> individual patches, these could ideally land through the Qualcomm tree
> with Mark's Ack.
>
> Measuring:
> * Before OPP / Interconnect patches reading all flash takes: ~3.4 seconds
> * After OPP / Interconnect patches reading all flash takes: ~4.7 seconds
> * After this patch reading all flash takes: ~3.3 seconds

Thanks Doug, I saw similar benefit on my setup with these patches. They do help
reduce the (unnecessary) additional overhead so it makes sense to merge these
along with the OPP/Interconnect patches in-order to avoid the regression.

Reviewed-by: Rajendra Nayak <rnayak@xxxxxxxxxxxxxx>
Tested-by: Rajendra Nayak <rnayak@xxxxxxxxxxxxxx>

> [1] https://lore.kernel.org/r/20200702004509.2333554-1-dianders@xxxxxxxxxxxx
> [2] https://lore.kernel.org/r/1593769293-6354-2-git-send-email-rnayak@xxxxxxxxxxxxxx
>
>
> Douglas Anderson (2):
>    spi: spi-qcom-qspi: Avoid clock setting if not needed
>    spi: spi-qcom-qspi: Set an autosuspend delay of 250 ms
>
>   drivers/spi/spi-qcom-qspi.c | 45 ++++++++++++++++++++++++++++---------
>   1 file changed, 35 insertions(+), 10 deletions(-)

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