[PATCH v2 0/2] Chunk splitting of spi transfers

Meghana Madhyastha meghana.madhyastha at gmail.com
Sat Feb 24 18:15:59 UTC 2018


I've added bcm2835_spi_transfer_one_message in spi-bcm2835. This calls
spi_split_transfers_maxsize to split large chunks for spi dma transfers. 
I then removed chunk splitting in the tinydrm spi helper (as now the core is
handling the chunk splitting). However, although the SPI HW should be able to
accomodate upto 65535 bytes for dma transfers, the splitting of chunks to 65535
bytes results in a dma transfer time out error. However, when the chunks are
split to <64  bytes it seems to work fine.

Changes in v2:
-Patch 2 did not exist in v1.

Meghana Madhyastha (2):
  drm/tinydrm: Remove chunk splitting in tinydrm_spi_transfer
  spi/spi-bcm2835: Add bcm2835_spi_transfer_one_message in spi-bcm2835.c

 drivers/gpu/drm/tinydrm/core/tinydrm-helpers.c | 48 ++++----------------------
 drivers/gpu/drm/tinydrm/mipi-dbi.c             | 10 ++----
 drivers/spi/spi-bcm2835.c                      | 29 ++++++++--------
 drivers/spi/spi.c                              |  5 ++-
 include/linux/spi/spi.h                        |  2 ++
 5 files changed, 27 insertions(+), 67 deletions(-)

-- 
2.11.0



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