libertas: increase spi driver thread priority (b26ed97c) · Commits · e / devices / android_kernel_xiaomi_markw

Currently, the libertas main thread contends with the spi driver thread in the TX path. To improve throughput, ensure that the driver thread has higher scheduling priority than the libertas main thread. Do this by making the libertas spi driver thread a low priority real time thread. We measured an average throughput improvement of 13%. Signed-off-by:

Anna Neal <anna@cozybit.com> Signed-off-by:

Andrey Yurovsky <andrey@cozybit.com> Signed-off-by:

John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/libertas/if_spi.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -1020,6 +1020,7 @@ static int __devinit if_spi_probe(struct spi_device *spi)
		struct libertas_spi_platform_data *pdata = spi->dev.platform_data;
		int err = 0;
		u32 scratch;
		struct sched_param param = { .sched_priority = 1 };

		lbs_deb_enter(LBS_DEB_SPI);

		@@ -1123,6 +1124,9 @@ static int __devinit if_spi_probe(struct spi_device *spi)
		lbs_pr_err("error creating SPI thread: err=%d\n", err);
		goto remove_card;
		}
		if (sched_setscheduler(card->spi_thread, SCHED_FIFO, &param))
		lbs_pr_err("Error setting scheduler, using default.\n");

		err = request_irq(spi->irq, if_spi_host_interrupt,
		IRQF_TRIGGER_FALLING, "libertas_spi", card);
		if (err) {