eckelmann.kpaste.net RSS- Lukas Wunner March 23, 2017, 10:36 a.m. UTC
- Commit 14af60b6fb3b ("spi/pl022: Add high priority message pump
- support") extended the pl022 driver to optionally run the message pump
- kworker thread with realtime priority, subject to a bool set by the
- platform.
- Commit ffbbdd21329f ("spi: create a message queueing infrastructure")
- moved a large portion of pl022 to generic code, making the realtime
- priority support available to other drivers.
- However the priority is set to MAX_RT_PRIO - 1, higher than most IRQs
- and identical to the CPU timer clock threads. This seems excessive so
- make the priority configurable.
- Cc: Mark Brown <broonie@kernel.org>
- Cc: Chris Blair <chris.blair@stericsson.com>
- Cc: Linus Walleij <linus.walleij@linaro.org>
- Cc: Mathias Duckeck <m.duckeck@kunbus.de>
- Signed-off-by: Lukas Wunner <lukas@wunner.de>
- ---
- drivers/spi/spi-pl022.c | 4 +++-
- drivers/spi/spi.c | 8 +++++---
- include/linux/spi/spi.h | 4 ++--
- 3 files changed, 10 insertions(+), 6 deletions(-)
- Comments
- Linus Walleij March 23, 2017, 1:10 p.m. UTC | #1
- On Thu, Mar 23, 2017 at 11:36 AM, Lukas Wunner <lukas@wunner.de> wrote:
- > Commit 14af60b6fb3b ("spi/pl022: Add high priority message pump
- > support") extended the pl022 driver to optionally run the message pump
- > kworker thread with realtime priority, subject to a bool set by the
- > platform.
- >
- > Commit ffbbdd21329f ("spi: create a message queueing infrastructure")
- > moved a large portion of pl022 to generic code, making the realtime
- > priority support available to other drivers.
- >
- > However the priority is set to MAX_RT_PRIO - 1, higher than most IRQs
- > and identical to the CPU timer clock threads. This seems excessive so
- > make the priority configurable.
- >
- > Cc: Mark Brown <broonie@kernel.org>
- > Cc: Chris Blair <chris.blair@stericsson.com>
- > Cc: Linus Walleij <linus.walleij@linaro.org>
- > Cc: Mathias Duckeck <m.duckeck@kunbus.de>
- > Signed-off-by: Lukas Wunner <lukas@wunner.de>
- Looks reasonable to me.
- Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
- Yours,
- Linus Walleij
- --
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- More majordomo info at http://vger.kernel.org/majordomo-info.html
- Patch
- diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
- index f7f7ba17b40e..f66cc3b6d489 100644
- --- a/drivers/spi/spi-pl022.c
- +++ b/drivers/spi/spi-pl022.c
- @@ -2153,9 +2153,11 @@ static int pl022_probe(struct amba_device *adev, const struct amba_id *id)
- master->auto_runtime_pm = true;
- master->transfer_one_message = pl022_transfer_one_message;
- master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
- - master->rt = platform_info->rt;
- master->dev.of_node = dev->of_node;
- + if (platform_info->rt)
- + master->rt_prio = MAX_RT_PRIO - 1;
- +
- if (platform_info->num_chipselect && platform_info->chipselects) {
- for (i = 0; i < num_cs; i++)
- pl022->chipselects[i] = platform_info->chipselects[i];
- diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
- index f699ea530b88..3220f6d87a66 100644
- --- a/drivers/spi/spi.c
- +++ b/drivers/spi/spi.c
- @@ -1286,7 +1286,7 @@ static void spi_pump_messages(struct kthread_work *work)
- static int spi_init_queue(struct spi_master *master)
- {
- - struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 };
- + struct sched_param param = { .sched_priority = master->rt_prio };
- master->running = false;
- master->busy = false;
- @@ -1308,9 +1308,10 @@ static int spi_init_queue(struct spi_master *master)
- * request and the scheduling of the message pump thread. Without this
- * setting the message pump thread will remain at default priority.
- */
- - if (master->rt) {
- + if (master->rt_prio >= 0 && master->rt_prio < MAX_RT_PRIO) {
- dev_info(&master->dev,
- - "will run message pump with realtime priority\n");
- + "will run message pump with realtime priority %d\n",
- + master->rt_prio);
- sched_setscheduler(master->kworker_task, SCHED_FIFO, ¶m);
- }
- @@ -1862,6 +1863,7 @@ struct spi_master *spi_alloc_master(struct device *dev, unsigned size)
- device_initialize(&master->dev);
- master->bus_num = -1;
- + master->rt_prio = -1;
- master->num_chipselect = 1;
- master->dev.class = &spi_master_class;
- master->dev.parent = dev;
- diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
- index 5a8c4b24f2dc..5ec405669668 100644
- --- a/include/linux/spi/spi.h
- +++ b/include/linux/spi/spi.h
- @@ -341,11 +341,11 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
- * @xfer_completion: used by core transfer_one_message()
- * @busy: message pump is busy
- * @running: message pump is running
- - * @rt: whether this queue is set to run as a realtime task
- * @auto_runtime_pm: the core should ensure a runtime PM reference is held
- * while the hardware is prepared, using the parent
- * device for the spidev
- * @max_dma_len: Maximum length of a DMA transfer for the device.
- + * @rt_prio: realtime priority of the message pump (-1 to use default prio)
- * @prepare_transfer_hardware: a message will soon arrive from the queue
- * so the subsystem requests the driver to prepare the transfer hardware
- * by issuing this call
- @@ -522,12 +522,12 @@ struct spi_master {
- bool idling;
- bool busy;
- bool running;
- - bool rt;
- bool auto_runtime_pm;
- bool cur_msg_prepared;
- bool cur_msg_mapped;
- struct completion xfer_completion;
- size_t max_dma_len;
- + int rt_prio;
- int (*prepare_transfer_hardware)(struct spi_master *master);
- int (*transfer_one_message)(struct spi_master *master,
jobrechner kworker flexible rt-prio patch
Posted by Anonymous on Wed 9th Jan 2019 12:50
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