David Jander dc3029056b spi: opportunistically skip ctlr->cur_msg_completion ... There are only a few drivers that do not call spi_finalize_current_message() in the context of transfer_one_message(), and even for those cases the completion ctlr->cur_msg_completion is not needed always. The calls to complete() and wait_for_completion() each take a spin-lock, which is costly. This patch makes it possible to avoid those calls in the big majority of cases, by introducing two flags that with the help of ordering via barriers can avoid using the completion safely. In case of a race with the context calling spi_finalize_current_message(), the scheme errs on the safe side and takes the completion. The impact of this patch is worth the effort: On a i.MX8MM SoC, the time the SPI bus is idle between two consecutive calls to spi_sync(), is reduced from 19.6us to 16.8us... roughly 15%. Signed-off-by: David Jander <david@protonic.nl> Link: https://lore.kernel.org/r/20220621061234.3626638-12-david@protonic.nl Signed-off-by: Mark Brown <broonie@kernel.org>		2022-06-27 13:27:26 +01:00
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ad7877.h
ads7846.h
altera.h
at73c213.h
at86rf230.h
cc2520.h
corgi_lcd.h
ds1305.h
eeprom.h
flash.h
libertas_spi.h
max7301.h	gpio: max730x: Make __max730x_remove() return void	2021-10-13 19:52:26 +02:00
mc33880.h
mmc_spi.h
mxs-spi.h
pxa2xx_spi.h	spi: pxa2xx_spi: Convert to use GPIO descriptors	2022-01-31 15:17:27 +00:00
rspi.h
s3c24xx-fiq.h
s3c24xx.h	spi: s3c24xx: Convert to GPIO descriptors	2022-01-24 13:37:34 +00:00
sh_hspi.h
sh_msiof.h
spi-fsl-dspi.h
spi-mem.h	spi: spi-mem: Add an ecc parameter to the spi_mem_op structure	2022-02-10 09:32:30 +01:00
spi.h	spi: opportunistically skip ctlr->cur_msg_completion	2022-06-27 13:27:26 +01:00
spi_bitbang.h
spi_gpio.h
spi_oc_tiny.h
tdo24m.h
tle62x0.h
xilinx_spi.h