[PATCH 5.4 125/214] spi: stm32: always perform registers configuration prior to transfer

Greg Kroah-Hartman
2020-09-01T15:33:45Z

From: Alain Volmat <alain.volmat@st.com>

[ Upstream commit 60ccb3515fc61a0124c70aa37317f75b67560024 ]

SPI registers content may have been lost upon suspend/resume sequence.
So, always compute and apply the necessary configuration in
stm32_spi_transfer_one_setup routine.

Signed-off-by: Alain Volmat <alain.volmat@st.com>
Link: https://lore.kernel.org/r/1597043558-29668-6-git-send-email-alain.volmat@st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/spi/spi-stm32.c | 42 +++++++++++++++++------------------------
1 file changed, 17 insertions(+), 25 deletions(-)

diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index 50ef03a8252d7..8146c2d91d307 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -1590,41 +1590,33 @@ static int stm32_spi_transfer_one_setup(struct stm32_spi *spi,
unsigned long flags;
unsigned int comm_type;
int nb_words, ret = 0;
+ int mbr;

spin_lock_irqsave(&spi->lock, flags);

spi->cur_xferlen = transfer->len;

- if (spi->cur_bpw != transfer->bits_per_word) {
- spi->cur_bpw = transfer->bits_per_word;
- spi->cfg->set_bpw(spi);
- }
-
- if (spi->cur_speed != transfer->speed_hz) {
- int mbr;
-
- /* Update spi->cur_speed with real clock speed */
- mbr = stm32_spi_prepare_mbr(spi, transfer->speed_hz,
- spi->cfg->baud_rate_div_min,
- spi->cfg->baud_rate_div_max);
- if (mbr < 0) {
- ret = mbr;
- goto out;
- }
+ spi->cur_bpw = transfer->bits_per_word;
+ spi->cfg->set_bpw(spi);

- transfer->speed_hz = spi->cur_speed;
- stm32_spi_set_mbr(spi, mbr);
+ /* Update spi->cur_speed with real clock speed */
+ mbr = stm32_spi_prepare_mbr(spi, transfer->speed_hz,
+ spi->cfg->baud_rate_div_min,
+ spi->cfg->baud_rate_div_max);
+ if (mbr < 0) {
+ ret = mbr;
+ goto out;
}

- comm_type = stm32_spi_communication_type(spi_dev, transfer);
- if (spi->cur_comm != comm_type) {
- ret = spi->cfg->set_mode(spi, comm_type);
+ transfer->speed_hz = spi->cur_speed;
+ stm32_spi_set_mbr(spi, mbr);

- if (ret < 0)
- goto out;
+ comm_type = stm32_spi_communication_type(spi_dev, transfer);
+ ret = spi->cfg->set_mode(spi, comm_type);
+ if (ret < 0)
+ goto out;

- spi->cur_comm = comm_type;
- }
+ spi->cur_comm = comm_type;

if (spi->cfg->set_data_idleness)
spi->cfg->set_data_idleness(spi, transfer->len);
--
2.25.1