[v2,0/4] Improves polling mode of s3c64xx driver

Message

Jaewon Kim April 19, 2023, 6:06 a.m. UTC

1.
s3cx64xx driver was supporting polling mode using quirk for SOC without DMA.
However, in order to use PIO mode as an optional rather than a quirk, when DMA
is not described, spi operates with pio mode rather than probe fail.

2.
Fixed the problem of high CPU usage in PIO mode.

3. 
If the transfer data size is larger than 32-bit, IRQ base PIO mode used.


Jaewon Kim (4):
  spi: s3c64xx: changed to PIO mode if there is no DMA
  spi: s3c64xx: add cpu_relax in polling loop
  spi: s3c64xx: add sleep during transfer
  spi: s3c64xx: support interrupt based pio mode

 drivers/spi/spi-s3c64xx.c                 | 85 ++++++++++++++++++++---
 include/linux/platform_data/spi-s3c64xx.h |  1 +
 2 files changed, 76 insertions(+), 10 deletions(-)

Comments

Krzysztof Kozlowski April 19, 2023, 7:59 a.m. UTC | #1

On 19/04/2023 08:06, Jaewon Kim wrote:
> 1.
> s3cx64xx driver was supporting polling mode using quirk for SOC without DMA.
> However, in order to use PIO mode as an optional rather than a quirk, when DMA
> is not described, spi operates with pio mode rather than probe fail.
> 
> 2.
> Fixed the problem of high CPU usage in PIO mode.
> 
> 3. 
> If the transfer data size is larger than 32-bit, IRQ base PIO mode used.
> 

What changed in the patches? You need to provide changelog.

Best regards,
Krzysztof

Jaewon Kim April 19, 2023, 8:29 a.m. UTC | #2

On 23. 4. 19. 16:59, Krzysztof Kozlowski wrote:
> On 19/04/2023 08:06, Jaewon Kim wrote:
>> 1.
>> s3cx64xx driver was supporting polling mode using quirk for SOC without DMA.
>> However, in order to use PIO mode as an optional rather than a quirk, when DMA
>> is not described, spi operates with pio mode rather than probe fail.
>>
>> 2.
>> Fixed the problem of high CPU usage in PIO mode.
>>
>> 3.
>> If the transfer data size is larger than 32-bit, IRQ base PIO mode used.
>>
> What changed in the patches? You need to provide changelog.


Oh, I missed changes while copy/pasting.

I will add changes v2 from v3 together.

Changes in V2.
- DeviceTree property not used to change PIO mod.
- Add cpu_releax() in polling loop
- Add lower limit in IRQ mode


>
> Best regards,
> Krzysztof
>
>
Thanks

Jaewon Kim