2020-08-05 07:06:05

by Alain Volmat

[permalink] [raw]

Subject: [PATCH 16/18] spi: stm32: always perform registers configuration prior to transfer

---

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 <[email protected]>
---
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 2665d8d7f318..177f82700de0 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -1579,41 +1579,33 @@ 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);
--
2.7.4

2020-08-05 20:11:06

by Mark Brown

[permalink] [raw]

Subject: Re: [PATCH 16/18] spi: stm32: always perform registers configuration prior to transfer

---

On Wed, Aug 05, 2020 at 09:02:11AM +0200, Alain Volmat wrote:
> 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.

This also.

---

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