* [email protected] <[email protected]> [091005 23:42]: > McSPI RX timeout issues are reported on some of the OMAP3 custom boards. > > After verifying configuration sequence in TRM, there seems to be issue with > McSPI configuration sequence. > > The steps to be followed for both TX and RX: > 1. Configure OMAP2_MCSPI_CHCONF0 register with required settings such as > TX/RX mode, word length, force chip select(if required). > 2. Set MS bit to 0 in OMAP2_MCSPI_CHCTRL0 register to provide the clock. > 3. Enable SPI channel in OMAP2_MCSPI_MODULCTRL > > But, the sequence used in current code seems to be wrong. Here it is: > 1. Set MS bit to 0 in OMAP2_MCSPI_CHCTRL0 register to provide the clock > (This is done during bootup) > 2. Enable SPI channel in OMAP2_MCSPI_MODULCTRL > 3. Configure OMAP2_MCSPI_CHCONF0 register with required settings such as > TX/RX mode, word length, force chip select(if required). > > After correcting configuration sequence, the timeout seems to be not > reproducible anymore.
Please resend this to the right lists one for merging: $ grep -A7 "SPI SUBSYSTEM" MAINTAINERS SPI SUBSYSTEM M: David Brownell <[email protected]> L: [email protected] S: Maintained F: Documentation/spi/ F: drivers/spi/ F: include/linux/spi/ Please also Cc linux-omap list too so people can easily keep track of it. Regards, Tony > > Signed-off-by: Manjunatha GK <[email protected]> > --- > drivers/spi/omap2_mcspi.c | 4 +++- > 1 files changed, 3 insertions(+), 1 deletions(-) > > diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c > index ba1a872..846485c 100644 > --- a/drivers/spi/omap2_mcspi.c > +++ b/drivers/spi/omap2_mcspi.c > @@ -802,7 +802,6 @@ static void omap2_mcspi_work(struct work_struct *work) > spi = m->spi; > cs = spi->controller_state; > > - omap2_mcspi_set_enable(spi, 1); > list_for_each_entry(t, &m->transfers, transfer_list) { > if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) { > status = -EINVAL; > @@ -830,6 +829,9 @@ static void omap2_mcspi_work(struct work_struct *work) > chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY; > mcspi_write_chconf0(spi, chconf); > > + omap2_mcspi_set_master_mode(mcspi->master); > + > + omap2_mcspi_set_enable(spi, 1); > if (t->len) { > unsigned count; > > -- > 1.6.0.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-omap" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
