blob: 37e76d894cb4eac4e960adeccc8dfbe2f694c892 [file] [log] [blame]
From 7223905929f916348961cc84f461e3d3452edf35 Mon Sep 17 00:00:00 2001
From: Boris Brezillon <boris.brezillon@bootlin.com>
Date: Sun, 22 Apr 2018 20:35:15 +0200
Subject: [PATCH 1275/1795] 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>
(cherry picked from commit 988f259b46646934003ff8ae4966f7233691d1ad)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
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 <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 ab173b06d147..0fb91af66efd 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -1523,6 +1523,22 @@ static int spi_controller_initialize_queue(struct spi_controller *ctlr)
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)
--
2.19.0