diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-12-23 14:44:08 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-12-23 14:44:08 -0800 |
| commit | 72a85e2b0a1e1e6fb4ee51ae902730212b2de25c (patch) | |
| tree | 9e96336280b5eaf21c00f03c7438bb463ac48e00 | |
| parent | 0a023cbb11e3d05c39dbb67317cb77ef22d47404 (diff) | |
| parent | 3b553e0041a65e499fa4e25ee146f01f4ec4e617 (diff) | |
Merge tag 'spi-fix-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi fix from Mark Brown:
"One driver specific change here which handles the case where a SPI
device for some reason tries to change the bus speed during a message
on fsl_spi hardware, this should be very unusual"
* tag 'spi-fix-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: fsl_spi: Don't change speed while chipselect is active
| -rw-r--r-- | drivers/spi/spi-fsl-spi.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c index 731624f157fc..93152144fd2e 100644 --- a/drivers/spi/spi-fsl-spi.c +++ b/drivers/spi/spi-fsl-spi.c @@ -333,13 +333,26 @@ static int fsl_spi_prepare_message(struct spi_controller *ctlr, { struct mpc8xxx_spi *mpc8xxx_spi = spi_controller_get_devdata(ctlr); struct spi_transfer *t; + struct spi_transfer *first; + + first = list_first_entry(&m->transfers, struct spi_transfer, + transfer_list); /* * In CPU mode, optimize large byte transfers to use larger * bits_per_word values to reduce number of interrupts taken. + * + * Some glitches can appear on the SPI clock when the mode changes. + * Check that there is no speed change during the transfer and set it up + * now to change the mode without having a chip-select asserted. */ - if (!(mpc8xxx_spi->flags & SPI_CPM_MODE)) { - list_for_each_entry(t, &m->transfers, transfer_list) { + list_for_each_entry(t, &m->transfers, transfer_list) { + if (t->speed_hz != first->speed_hz) { + dev_err(&m->spi->dev, + "speed_hz cannot change during message.\n"); + return -EINVAL; + } + if (!(mpc8xxx_spi->flags & SPI_CPM_MODE)) { if (t->len < 256 || t->bits_per_word != 8) continue; if ((t->len & 3) == 0) @@ -348,7 +361,7 @@ static int fsl_spi_prepare_message(struct spi_controller *ctlr, t->bits_per_word = 16; } } - return 0; + return fsl_spi_setup_transfer(m->spi, first); } static int fsl_spi_transfer_one(struct spi_controller *controller, |