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

[Jaewon Kim]

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(-)

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2.17.1