[PATCH v1] spi: cadence-qspi: Fix exec_mem_op error handling

[Emanuele Ghidoli <ghidoliemanuele@gmail.com>]

From: Emanuele Ghidoli <emanuele.ghidoli@toradex.com>

cqspi_exec_mem_op() increments the runtime PM usage counter before all
refcount checks are performed. If one of these checks fails, the function
returns without dropping the PM reference.

Move the pm_runtime_resume_and_get() call after the refcount checks so
that runtime PM is only acquired when the operation can proceed and
drop the inflight_ops refcount if the PM resume fails.

Cc: stable@vger.kernel.org
Fixes: 7446284023e8 ("spi: cadence-quadspi: Implement refcount to handle unbind during busy")
Signed-off-by: Emanuele Ghidoli <emanuele.ghidoli@toradex.com>
---
 drivers/spi/spi-cadence-quadspi.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
index 5fb0cb07c110..2ead419e896e 100644
--- a/drivers/spi/spi-cadence-quadspi.c
+++ b/drivers/spi/spi-cadence-quadspi.c
@@ -1483,14 +1483,6 @@ static int cqspi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
 	if (refcount_read(&cqspi->inflight_ops) == 0)
 		return -ENODEV;
 
-	if (!(ddata && (ddata->quirks & CQSPI_DISABLE_RUNTIME_PM))) {
-		ret = pm_runtime_resume_and_get(dev);
-		if (ret) {
-			dev_err(&mem->spi->dev, "resume failed with %d\n", ret);
-			return ret;
-		}
-	}
-
 	if (!refcount_read(&cqspi->refcount))
 		return -EBUSY;
 
@@ -1502,6 +1494,14 @@ static int cqspi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
 		return -EBUSY;
 	}
 
+	if (!(ddata && (ddata->quirks & CQSPI_DISABLE_RUNTIME_PM))) {
+		ret = pm_runtime_resume_and_get(dev);
+		if (ret) {
+			dev_err(&mem->spi->dev, "resume failed with %d\n", ret);
+			goto dec_inflight_refcount;
+		}
+	}
+
 	ret = cqspi_mem_process(mem, op);
 
 	if (!(ddata && (ddata->quirks & CQSPI_DISABLE_RUNTIME_PM)))
@@ -1510,6 +1510,7 @@ static int cqspi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
 	if (ret)
 		dev_err(&mem->spi->dev, "operation failed with %d\n", ret);
 
+dec_inflight_refcount:
 	if (refcount_read(&cqspi->inflight_ops) > 1)
 		refcount_dec(&cqspi->inflight_ops);
 
-- 
2.43.0