spi: davinci: Drop the preload of TX buffer before read/writes operations
A write to the TX buffer is performed before entering the loop to "avoid
clock starvation". This sometimes results in subsequent writes in
davinci_spi_xfer_data() to occur while the TXFULL bit is asserted,
leading to write failures.
Remove the preload of the TX buffer.
Signed-off-by: Bastien Curutchet <bastien.curutchet@bootlin.com>
diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c
index 8204987..19bd06cf 100644
--- a/drivers/spi/davinci_spi.c
+++ b/drivers/spi/davinci_spi.c
@@ -129,9 +129,6 @@
while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
;
- /* preload the TX buffer to avoid clock starvation */
- writel(data1_reg_val, &ds->regs->dat1);
-
/* keep reading 1 byte until only 1 byte left */
while ((len--) > 1)
*rxp++ = davinci_spi_xfer_data(ds, data1_reg_val);
@@ -159,12 +156,6 @@
while (readl(&ds->regs->buf) & SPIBUF_TXFULL_MASK)
;
- /* preload the TX buffer to avoid clock starvation */
- if (len > 2) {
- writel(data1_reg_val | *txp++, &ds->regs->dat1);
- len--;
- }
-
/* keep writing 1 byte until only 1 byte left */
while ((len--) > 1)
davinci_spi_xfer_data(ds, data1_reg_val | *txp++);