diff options
| author | Stefan Roese <sr@denx.de> | 2014-01-31 13:44:59 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-01-16 06:59:34 -0800 |
| commit | 2937d5ac11c421a02f276295f388994027bbe607 (patch) | |
| tree | f09d92cf639952150866441235de698edbce10b0 | |
| parent | ceaefcdf2a9f24835691d58d45c5cc50d596a7d0 (diff) | |
| download | lwn-2937d5ac11c421a02f276295f388994027bbe607.tar.gz lwn-2937d5ac11c421a02f276295f388994027bbe607.zip | |
spi: fsl: Fix problem with multi message transfers
commit 4302a59629f7a0bd70fd1605d2b558597517372a upstream.
When used via spidev with more than one messages to tranfer via
SPI_IOC_MESSAGE the current implementation would return with
-EINVAL, since bits_per_word and speed_hz are set in all
transfer structs. And in the 2nd loop status will stay at
-EINVAL as its not overwritten again via fsl_spi_setup_transfer().
This patch changes this behavious by first checking if one of
the messages uses different settings. If this is the case
the function will return with -EINVAL. If not, the messages
are transferred correctly.
Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: Esben Haabendal <esbenhaabendal@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/spi/spi-fsl-spi.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c index 119f7af94537..4dcb2929c01f 100644 --- a/drivers/spi/spi-fsl-spi.c +++ b/drivers/spi/spi-fsl-spi.c @@ -362,18 +362,28 @@ static int fsl_spi_bufs(struct spi_device *spi, struct spi_transfer *t, static void fsl_spi_do_one_msg(struct spi_message *m) { struct spi_device *spi = m->spi; - struct spi_transfer *t; + struct spi_transfer *t, *first; unsigned int cs_change; const int nsecs = 50; int status; - cs_change = 1; - status = 0; + /* Don't allow changes if CS is active */ + first = list_first_entry(&m->transfers, struct spi_transfer, + transfer_list); list_for_each_entry(t, &m->transfers, transfer_list) { - if (t->bits_per_word || t->speed_hz) { - /* Don't allow changes if CS is active */ + if ((first->bits_per_word != t->bits_per_word) || + (first->speed_hz != t->speed_hz)) { status = -EINVAL; + dev_err(&spi->dev, + "bits_per_word/speed_hz should be same for the same SPI transfer\n"); + return; + } + } + cs_change = 1; + status = -EINVAL; + list_for_each_entry(t, &m->transfers, transfer_list) { + if (t->bits_per_word || t->speed_hz) { if (cs_change) status = fsl_spi_setup_transfer(spi, t); if (status < 0) |