[PATCH 5/5] spi: Reduce kthread priority

[Peter Zijlstra]

The SPI thingies request FIFO-99 by default, reduce this to FIFO-50.

FIFO-99 is the very highest priority available to SCHED_FIFO and
it not a suitable default; it would indicate the SPI work is the
most important work on the machine.

Cc: Benson Leung <ble...@chromium.org>
Cc: Enric Balletbo i Serra <enric.balle...@collabora.com>
Cc: Guenter Roeck <gro...@chromium.org>
Cc: Mark Brown <broo...@kernel.org>
Cc: linux-...@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
---
 drivers/platform/chrome/cros_ec_spi.c |    2 +-
 drivers/spi/spi.c                     |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/platform/chrome/cros_ec_spi.c
+++ b/drivers/platform/chrome/cros_ec_spi.c
@@ -706,7 +706,7 @@ static int cros_ec_spi_devm_high_pri_all
                                           struct cros_ec_spi *ec_spi)
 {
        struct sched_param sched_priority = {
-               .sched_priority = MAX_RT_PRIO - 1,
+               .sched_priority = MAX_RT_PRIO / 2,
        };
        int err;
 
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1434,7 +1434,7 @@ static void spi_pump_messages(struct kth
  */
 static void spi_set_thread_rt(struct spi_controller *ctlr)
 {
-       struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
+       struct sched_param param = { .sched_priority = MAX_RT_PRIO / 2 };
 
        dev_info(&ctlr->dev,
                "will run message pump with realtime priority\n");