[PATCH 5.10 073/152] spi: altera: fix return value for altera_spi_txrx()

From: Greg Kroah-Hartman
Date: Mon Jan 18 2021 - 09:23:08 EST


From: Xu Yilun <yilun.xu@xxxxxxxxx>

[ Upstream commit ede090f5a438e97d0586f64067bbb956e30a2a31 ]

This patch fixes the return value for altera_spi_txrx. It should return
1 for interrupt transfer mode, and return 0 for polling transfer mode.

The altera_spi_txrx() implements the spi_controller.transfer_one
callback. According to the spi-summary.rst, the transfer_one should
return 0 when transfer is finished, return 1 when transfer is still in
progress.

Signed-off-by: Xu Yilun <yilun.xu@xxxxxxxxx>
Link: https://lore.kernel.org/r/1609219662-27057-2-git-send-email-yilun.xu@xxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/spi/spi-altera.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/spi/spi-altera.c b/drivers/spi/spi-altera.c
index 809bfff3690ab..cbc4c28c1541c 100644
--- a/drivers/spi/spi-altera.c
+++ b/drivers/spi/spi-altera.c
@@ -189,24 +189,26 @@ static int altera_spi_txrx(struct spi_master *master,

/* send the first byte */
altera_spi_tx_word(hw);
- } else {
- while (hw->count < hw->len) {
- altera_spi_tx_word(hw);

- for (;;) {
- altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
- if (val & ALTERA_SPI_STATUS_RRDY_MSK)
- break;
+ return 1;
+ }
+
+ while (hw->count < hw->len) {
+ altera_spi_tx_word(hw);

- cpu_relax();
- }
+ for (;;) {
+ altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
+ if (val & ALTERA_SPI_STATUS_RRDY_MSK)
+ break;

- altera_spi_rx_word(hw);
+ cpu_relax();
}
- spi_finalize_current_transfer(master);
+
+ altera_spi_rx_word(hw);
}
+ spi_finalize_current_transfer(master);

- return t->len;
+ return 0;
}

static irqreturn_t altera_spi_irq(int irq, void *dev)
--
2.27.0