Commit 62826970 authored Feb 15, 2016 by Mark Brown

spi: Add cond_resched() in main message processing loop



When a controller has only PIO support it is very likely that we will
run into use cases where we spend a very large amount of time consuming
CPU.  Code that does this should call cond_resched() every once in a
while to give other tasks more of a chance to run so do that in the main
SPI loop, the overhead is negligable if it's not needed.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

parent 556351f1

drivers/spi/spi.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -1184,6 +1184,9 @@ static void __spi_pump_messages(struct spi_master *master, bool in_kthread)
		return;
		}
		mutex_unlock(&master->bus_lock_mutex);

		/* Prod the scheduler in case transfer_one() was busy waiting */
		cond_resched();
		}

		/**

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