spi: bcm2835: fill/drain SPI-fifo as much as possible during interrupt

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Implement the recommendation from the BCM2835 data-sheet
with regards to polling drivers to fill/drain the FIFO as much data as possible
also for the interrupt-driven case (which this driver is making use of).

This means that for long transfers (>64bytes) we need one interrupt
every 64 bytes instead of every 12 bytes, as the FIFO is 16 words (not bytes) wide.

Tested with mcp251x (can bus), fb_st7735 (TFT framebuffer device)
and enc28j60 (ethernet) drivers.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

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Martin Sperl 2015-03-23 15:11:53 +01:00 • committed by Mark Brown

parent 342f948a16

commit 4adf312976

1 changed files with 17 additions and 61 deletions

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drivers/spi/spi-bcm2835.c

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