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

Message

Doug Anderson July 7, 2020, 8:16 p.m. UTC

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

[1] https://lore.kernel.org/r/[e-mail]
[2] https://lore.kernel.org/r/[e-mail]


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(-)

Comments

Rajendra Nayak July 8, 2020, 8:39 a.m. UTC | #1

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 <[e-mail]>
Tested-by: Rajendra Nayak <[e-mail]>

> 
> [1] https://lore.kernel.org/r/[e-mail]
> [2] https://lore.kernel.org/r/[e-mail]
> 
> 
> 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(-)
>

Mukesh, Savaliya July 9, 2020, 6:50 a.m. UTC | #2

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
>
> [1] https://lore.kernel.org/r/[e-mail]
> [2] https://lore.kernel.org/r/[e-mail]
>
>
> 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(-)

Reviewed-by: Mukesh Kumar Savaliya <[e-mail]>