[PATCH v2 3/5] spi: spi-mem: Add lock context annotations

[Joseph CT Chan <jctchan@gmail.com>]

From: Bart Van Assche <bvanassche@acm.org>

Annotate spi_mem_access_start() with __cond_acquires() and
spi_mem_access_end() with __releases() for both bus_lock_mutex and
io_mutex in drivers/spi/spi-mem.c. Enable static context analysis to
track controller lock ownership across SPI memory operations without
false positive lock imbalance warnings.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Joseph CT Chan <josephctchan@google.com>
---
 drivers/spi/spi-mem.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index b94680b60af9..f115ef6bf53b 100644
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -297,6 +297,8 @@ bool spi_mem_supports_op(struct spi_mem *mem, const struct spi_mem_op *op)
 EXPORT_SYMBOL_GPL(spi_mem_supports_op);
 
 static int spi_mem_access_start(struct spi_mem *mem)
+	__cond_acquires(0, &mem->spi->controller->bus_lock_mutex)
+	__cond_acquires(0, &mem->spi->controller->io_mutex)
 {
 	struct spi_controller *ctlr = mem->spi->controller;
 
@@ -324,6 +326,8 @@ static int spi_mem_access_start(struct spi_mem *mem)
 }
 
 static void spi_mem_access_end(struct spi_mem *mem)
+	__releases(&mem->spi->controller->io_mutex)
+	__releases(&mem->spi->controller->bus_lock_mutex)
 {
 	struct spi_controller *ctlr = mem->spi->controller;
 
-- 
2.56.0.385.gac671c819a-goog