[PATCH v3 2/2] spi: axi-spi-engine: fix stale SYNC IRQ pending in trigger_enable

[Jonathan Santos]

spi_engine_trigger_enable() sends SYNC(1) and polls SYNC_ID, it never
clears the INT_PENDING[SYNC] bit afterward. This leaves a stale pending
interrupt that can fire spuriously when INT_SYNC is later enabled.

Simillarly to the fix on spi_engine_setup(), clear INT_PENDING[SYNC]
after polling the SYNC_ID.

Fixes: 8fc13b822c74 ("spi: axi-spi-engine: don't repeat mode config for offload")
Reviewed-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
Signed-off-by: Jonathan Santos <Jonathan.Santos@xxxxxxxxxx>
---
 drivers/spi/spi-axi-spi-engine.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c
index 87c05cb064cc..ead5b295e680 100644
--- a/drivers/spi/spi-axi-spi-engine.c
+++ b/drivers/spi/spi-axi-spi-engine.c
@@ -1036,7 +1036,13 @@ static int spi_engine_trigger_enable(struct spi_offload *offload)
 		spi_engine->base + SPI_ENGINE_REG_CMD_FIFO);
 
 	ret = readl_relaxed_poll_timeout(spi_engine->base + SPI_ENGINE_REG_SYNC_ID,
-					 reg, reg == 1, 1, 1000);
+					 reg, reg == 1, 1, 1 * USEC_PER_MSEC);
+
+	/* Clear the stale SYNC pending bit so it doesn't fire when the IRQ is later enabled */
+	writel_relaxed(SPI_ENGINE_INT_SYNC, spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
+	/* Read back to flush posted write. */
+	readl_relaxed(spi_engine->base + SPI_ENGINE_REG_INT_PENDING);
+
 	if (ret)
 		return ret;
 
-- 
2.34.1