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spi: davinci: Drop the preload of TX buffer before read/writes operations

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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>
This commit is contained in:
Bastien Curutchet
2024-09-20 10:28:06 +02:00
committed by Tom Rini
parent 7bc5f66f55
commit 983fd3d06d
1 changed files with 0 additions and 9 deletions
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9
drivers/spi/davinci_spi.c
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@@ -129,9 +129,6 @@ static int davinci_spi_read(struct davinci_spi_slave *ds, unsigned int len,
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 @@ static int davinci_spi_write(struct davinci_spi_slave *ds, unsigned int len,
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++);