[Patch 5/9] spi: bcm-qspi: when tx/rx buffer is NULL set to 0

From: Kamal Dasu
Date: Thu Apr 16 2020 - 13:43:45 EST


Currently we set the tx/rx buffer to 0xff when NULL. This causes
problems with some spi slaves where 0xff is a valid command. Looking
at other drivers, the tx/rx buffer is usually set to 0x00 when NULL.
Following this convention solves the issue.

Fixes: fa236a7ef240 ("spi: bcm-qspi: Add Broadcom MSPI driver")
Signed-off-by: Justin Chen <justinpopo6@xxxxxxxxx>
Signed-off-by: Kamal Dasu <kdasu.kdev@xxxxxxxxx>
---
drivers/spi/spi-bcm-qspi.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c
index c48c399dce53..e00208801c8b 100644
--- a/drivers/spi/spi-bcm-qspi.c
+++ b/drivers/spi/spi-bcm-qspi.c
@@ -669,7 +669,7 @@ static void read_from_hw(struct bcm_qspi *qspi, int slots)
if (buf)
buf[tp.byte] = read_rxram_slot_u8(qspi, slot);
dev_dbg(&qspi->pdev->dev, "RD %02x\n",
- buf ? buf[tp.byte] : 0xff);
+ buf ? buf[tp.byte] : 0x0);
} else {
u16 *buf = tp.trans->rx_buf;

@@ -677,7 +677,7 @@ static void read_from_hw(struct bcm_qspi *qspi, int slots)
buf[tp.byte / 2] = read_rxram_slot_u16(qspi,
slot);
dev_dbg(&qspi->pdev->dev, "RD %04x\n",
- buf ? buf[tp.byte] : 0xffff);
+ buf ? buf[tp.byte / 2] : 0x0);
}

update_qspi_trans_byte_count(qspi, &tp,
@@ -732,13 +732,13 @@ static int write_to_hw(struct bcm_qspi *qspi, struct spi_device *spi)
while (!tstatus && slot < MSPI_NUM_CDRAM) {
if (tp.trans->bits_per_word <= 8) {
const u8 *buf = tp.trans->tx_buf;
- u8 val = buf ? buf[tp.byte] : 0xff;
+ u8 val = buf ? buf[tp.byte] : 0x00;

write_txram_slot_u8(qspi, slot, val);
dev_dbg(&qspi->pdev->dev, "WR %02x\n", val);
} else {
const u16 *buf = tp.trans->tx_buf;
- u16 val = buf ? buf[tp.byte / 2] : 0xffff;
+ u16 val = buf ? buf[tp.byte / 2] : 0x0000;

write_txram_slot_u16(qspi, slot, val);
dev_dbg(&qspi->pdev->dev, "WR %04x\n", val);
--
2.17.1