From 988f259b46646934003ff8ae4966f7233691d1ad Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Sun, 22 Apr 2018 20:35:15 +0200 Subject: [PATCH] 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 Signed-off-by: Mark Brown --- drivers/spi/internals.h | 2 ++ drivers/spi/spi.c | 16 ++++++++++++++++ 2 files changed, 18 insertions(+) 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 #include +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)