From 14af60b6fb3b76634278364b697dae2f9f360abf Mon Sep 17 00:00:00 2001 From: Chris Blair Date: Thu, 2 Feb 2012 13:59:34 +0100 Subject: spi/pl022: Add high priority message pump support This switches the PL022 worker to a kthread in order to get hold of a mechanism to control the message pump priority. On low-latency systems elevating the message kthread to realtime priority give a real sleek response curve. This has been confirmed by measurements. Realtime priority elevation for a certain PL022 port can be requested from platform data. Cc: Mark Brown Acked-by: Viresh Kumar Signed-off-by: Chris Blair Signed-off-by: Linus Walleij Signed-off-by: Grant Likely --- include/linux/amba/pl022.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/amba') diff --git a/include/linux/amba/pl022.h b/include/linux/amba/pl022.h index 572f637299c..3672f40f345 100644 --- a/include/linux/amba/pl022.h +++ b/include/linux/amba/pl022.h @@ -241,6 +241,8 @@ struct dma_chan; * @autosuspend_delay: delay in ms following transfer completion before the * runtime power management system suspends the device. A setting of 0 * indicates no delay and the device will be suspended immediately. + * @rt: indicates the controller should run the message pump with realtime + * priority to minimise the transfer latency on the bus. */ struct pl022_ssp_controller { u16 bus_id; @@ -250,6 +252,7 @@ struct pl022_ssp_controller { void *dma_rx_param; void *dma_tx_param; int autosuspend_delay; + bool rt; }; /** -- cgit v1.2.3-70-g09d2