Re: 回信: [RFC PATCH 08/10] spi: mxic: Fix the transmit path

By working with external hardware ECC engines, we figured out that
Under certain circumstances, it is needed for the SPI controller to
check INT_TX_EMPTY and INT_RX_NOT_EMPTY in both receive and transmit
path (not only in the receive path). The delay penalty being
negligible, move this code in the common path.

Fixes: b942d80b0a39 ("spi: Add MXIC controller driver")
Cc: stable@vger.kernel.org
Suggested-by: Mason Yang <redacted>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/spi/spi-mxic.c | 28 ++++++++++++----------------
 1 file changed, 12 insertions(+), 16 deletions(-)

diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c
index 96b418293bf2..4fb19e6f94b0 100644
--- a/drivers/spi/spi-mxic.c
+++ b/drivers/spi/spi-mxic.c

@@ -304,25 +304,21 @@ static int mxic_spi_data_xfer(struct mxic_spi 

*mxic, const void *txbuf,

       writel(data, mxic->regs + TXD(nbytes % 4));

+      ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
+                sts & INT_TX_EMPTY, 0, USEC_PER_SEC);
+      if (ret)
+         return ret;
+
+      ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
+                sts & INT_RX_NOT_EMPTY, 0,
+                USEC_PER_SEC);
+      if (ret)
+         return ret;
+
+      data = readl(mxic->regs + RXD);
       if (rxbuf) {
-         ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
-                   sts & INT_TX_EMPTY, 0,
-                   USEC_PER_SEC);
-         if (ret)
-            return ret;
-
-         ret = readl_poll_timeout(mxic->regs + INT_STS, sts,
-                   sts & INT_RX_NOT_EMPTY, 0,
-                   USEC_PER_SEC);
-         if (ret)
-            return ret;
-
-         data = readl(mxic->regs + RXD);
          data >>= (8 * (4 - nbytes));
          memcpy(rxbuf + pos, &data, nbytes);
-         WARN_ON(readl(mxic->regs + INT_STS) & INT_RX_NOT_EMPTY);
-      } else {
-         readl(mxic->regs + RXD);
       }
       WARN_ON(readl(mxic->regs + INT_STS) & INT_RX_NOT_EMPTY);

-- 
2.27.0