[PATCH v3 4/7] spi: cadence-xspi: Clear "SDMA ready" IRQ flag after polling

[Paul Cercueil <paul.cercueil@bootlin.com>]

From: Tanmay Jagdale <tanmay@marvell.com>

When polling for the "SDMA ready" event, once the corresponding bit is
set in the CDNS_XSPI_SDMA_TRIGGER we should reset it to zero. Otherwise,
any subsequent call to cdns_xspi_is_sdma_ready() will just return early.

Fixes: 931e389ded0f ("spi: cadence: Add Marvell xfer operation support")
Cc: stable@vger.kernel.org
Signed-off-by: Tanmay Jagdale <tanmay@marvell.com>
Co-developed-by: Paul Cercueil <paul.cercueil@bootlin.com>
Signed-off-by: Paul Cercueil <paul.cercueil@bootlin.com>
---

Notes:
    v2: New patch
    
    v3: No change

 drivers/spi/spi-cadence-xspi.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi-cadence-xspi.c b/drivers/spi/spi-cadence-xspi.c
index 39c868a5b171..095bf640b379 100644
--- a/drivers/spi/spi-cadence-xspi.c
+++ b/drivers/spi/spi-cadence-xspi.c
@@ -1068,12 +1068,20 @@ static bool cdns_xspi_is_sdma_ready(struct cdns_xspi_dev *cdns_xspi, bool sleep)
 {
 	u32 ctrl_stat;
 
-	return !readl_relaxed_poll_timeout
-		(cdns_xspi->iobase + CDNS_XSPI_INTR_STATUS_REG,
-		ctrl_stat,
-		(ctrl_stat & CDNS_XSPI_SDMA_TRIGGER),
-		sleep ? MRVL_XSPI_POLL_DELAY_US : 0,
-		sleep ? MRVL_XSPI_POLL_TIMEOUT_US : 0);
+	if (readl_relaxed_poll_timeout
+	    (cdns_xspi->iobase + CDNS_XSPI_INTR_STATUS_REG,
+	     ctrl_stat,
+	     (ctrl_stat & CDNS_XSPI_SDMA_TRIGGER),
+	     sleep ? MRVL_XSPI_POLL_DELAY_US : 0,
+	     sleep ? MRVL_XSPI_POLL_TIMEOUT_US : 0)) {
+		return false;
+	}
+
+	/* Clear the flag */
+	writel(CDNS_XSPI_SDMA_TRIGGER,
+	       cdns_xspi->iobase + CDNS_XSPI_INTR_STATUS_REG);
+
+	return true;
 }
 
 static int cdns_xspi_transfer_one_message_b0(struct spi_controller *controller,
-- 
2.47.3