diff options
| author |   Boris Brezillon <boris.brezillon@bootlin.com> | 2018-04-22 20:35:15 +0200 |
|---|---|---|
| committer |   Mark Brown <broonie@kernel.org> | 2018-04-23 15:48:18 +0100 |
| commit | 988f259b46646934003ff8ae4966f7233691d1ad (patch) | |
| tree | 8065f35dce6e5c4fd910a03916625c8b74083ccd /drivers/spi | |
| parent | spi: Expose spi_{map,unmap}_buf() for internal use (diff) | |
| download | linux-dev-988f259b46646934003ff8ae4966f7233691d1ad.tar.xz linux-dev-988f259b46646934003ff8ae4966f7233691d1ad.zip | |
spi: Add an helper to flush the message queue
This is needed by the spi-mem logic to force all messages that have been
queued before a memory operation to be sent before we start the memory
operation. We do that in order to guarantee that spi-mem operations do
not preempt regular SPI transfers.
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/internals.h | 2 | ||||
| -rw-r--r-- | drivers/spi/spi.c | 16 |
2 files changed, 18 insertions, 0 deletions
diff --git a/drivers/spi/internals.h b/drivers/spi/internals.h index dbe56c77b464..4a28a8395552 100644 --- a/drivers/spi/internals.h +++ b/drivers/spi/internals.h @@ -17,6 +17,8 @@ #include <linux/scatterlist.h> #include <linux/spi/spi.h> +void spi_flush_queue(struct spi_controller *ctrl); + #ifdef CONFIG_HAS_DMA int spi_map_buf(struct spi_controller *ctlr, struct device *dev, struct sg_table *sgt, void *buf, size_t len, diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 86b778d8563e..3f4666365678 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1522,6 +1522,22 @@ err_init_queue: return ret; } +/** + * spi_flush_queue - Send all pending messages in the queue from the callers' + * context + * @ctlr: controller to process queue for + * + * This should be used when one wants to ensure all pending messages have been + * sent before doing something. Is used by the spi-mem code to make sure SPI + * memory operations do not preempt regular SPI transfers that have been queued + * before the spi-mem operation. + */ +void spi_flush_queue(struct spi_controller *ctlr) +{ + if (ctlr->transfer == spi_queued_transfer) + __spi_pump_messages(ctlr, false); +} + /*-------------------------------------------------------------------------*/ #if defined(CONFIG_OF) |