[U-Boot] [PATCH] driver: fsl_qspi: disable AHB buffer prefetch

[Yunhui Cui]

From: Yunhui Cui <yunhui.cui at nxp.com>

A-009282: QuadSPI: QuadSPI data pre-fetch can result in incorrect data
Affects: QuadSPI
Description: With AHB buffer prefetch enabled, the QuadSPI may return
incorrect data on the AHB interface. The buffer pre-fetch is enabled
if the fetch size as configured either in the LUT or in the BUFxCR register
is greater than 8 bytes.
Impact: Only 64 bit read allowed.
Workaround: Keep the read data size to 64 bits (8 Bytes), which disables
the prefetch on the AHB buffer,
and prevents this issue from occurring.

Signed-off-by: Yunhui Cui <yunhui.cui at nxp.com>
---
 drivers/spi/fsl_qspi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/fsl_qspi.c b/drivers/spi/fsl_qspi.c
index 75cbab2..e0a002d 100644
--- a/drivers/spi/fsl_qspi.c
+++ b/drivers/spi/fsl_qspi.c
@@ -444,7 +444,7 @@ static void qspi_init_ahb_read(struct fsl_qspi_priv *priv)
 	qspi_write32(priv->flags, &regs->buf1cr, QSPI_BUFXCR_INVALID_MSTRID);
 	qspi_write32(priv->flags, &regs->buf2cr, QSPI_BUFXCR_INVALID_MSTRID);
 	qspi_write32(priv->flags, &regs->buf3cr, QSPI_BUF3CR_ALLMST_MASK |
-		     (0x80 << QSPI_BUF3CR_ADATSZ_SHIFT));
+		     (0x1 << QSPI_BUF3CR_ADATSZ_SHIFT));
 
 	/* We only use the buffer3 */
 	qspi_write32(priv->flags, &regs->buf0ind, 0);
-- 
2.1.0.27.g96db324