[U-Boot] [PATCH v3] driver: spi: fsl-qspi: disable AHB buffer prefetch

[Yunhui Cui]

From: Yunhui Cui <yunhui....@nxp.com>

Errata: A-009282: QuadSPI data pre-fetch can result in incorrect data
We need this errata workaround when CONFIG_SYS_FSL_QSPI_AHB is enabled.

Signed-off-by: Yunhui Cui <yunhui....@nxp.com>
---
 drivers/spi/fsl_qspi.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/fsl_qspi.c b/drivers/spi/fsl_qspi.c
index 75cbab2..0354e20 100644
--- a/drivers/spi/fsl_qspi.c
+++ b/drivers/spi/fsl_qspi.c
@@ -438,13 +438,23 @@ static void qspi_enable_ddr_mode(struct fsl_qspi_priv 
*priv)
 static void qspi_init_ahb_read(struct fsl_qspi_priv *priv)
 {
        struct fsl_qspi_regs *regs = priv->regs;
+       int rx_size = 0x80;
 
        /* AHB configuration for access buffer 0/1/2 .*/
        qspi_write32(priv->flags, &regs->buf0cr, QSPI_BUFXCR_INVALID_MSTRID);
        qspi_write32(priv->flags, &regs->buf1cr, QSPI_BUFXCR_INVALID_MSTRID);
        qspi_write32(priv->flags, &regs->buf2cr, QSPI_BUFXCR_INVALID_MSTRID);
+
+#ifdef CONFIG_SYS_FSL_ERRATUM_A009282
+       /*A-009282: QuadSPI data pre-fetch can result in incorrect data
+        *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.
+       */
+       rx_size = 0x1;
+#endif
        qspi_write32(priv->flags, &regs->buf3cr, QSPI_BUF3CR_ALLMST_MASK |
-                    (0x80 << QSPI_BUF3CR_ADATSZ_SHIFT));
+                    (rx_size << QSPI_BUF3CR_ADATSZ_SHIFT));
 
        /* We only use the buffer3 */
        qspi_write32(priv->flags, &regs->buf0ind, 0);
-- 
2.1.0.27.g96db324

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