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
diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c
index 731624f..9315214 100644
--- a/drivers/spi/spi-fsl-spi.c
+++ b/drivers/spi/spi-fsl-spi.c
@@ -333,13 +333,26 @@
{
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 @@
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,
