Hi Andy, On 6/15/2017 1:21 AM, Andy Gross wrote: > On Wed, Jun 14, 2017 at 12:43:43PM +0530, Sricharan R wrote: >> Hi Varada, >> >> On 6/14/2017 11:22 AM, Varadarajan Narayanan wrote: >>> Wait to signal done until we get all of the interrupts we are expecting >>> to get for a transaction. If we don't wait for the input done flag, we >>> can be inbetween transactions when the done flag comes in and this can >>> mess up the next transaction. >>> >>> Signed-off-by: Andy Gross <andy.gross@xxxxxxxxxx> >>> Signed-off-by: Varadarajan Narayanan <varada@xxxxxxxxxxxxxx> >>> --- >>> drivers/spi/spi-qup.c | 3 ++- >>> 1 file changed, 2 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c >>> index 2124815..7c22ee4 100644 >>> --- a/drivers/spi/spi-qup.c >>> +++ b/drivers/spi/spi-qup.c >>> @@ -465,7 +465,8 @@ static irqreturn_t spi_qup_qup_irq(int irq, void *dev_id) >>> controller->xfer = xfer; >>> spin_unlock_irqrestore(&controller->lock, flags); >>> >>> - if (controller->rx_bytes == xfer->len || error) >>> + if ((controller->rx_bytes == xfer->len && >>> + (opflags & QUP_OP_MAX_INPUT_DONE_FLAG)) || error) >> >> Not sure why we need this additional check, because having read all the >> bytes implies transfer complete (or) why not just check only for >> QUP_OP_MAX_INPUT_DONE_FLAG ? > > So you can receive an interrupt for the last data without it having also > signalled the INPUT_DONE. That means you'd have one more IRQ come in and if you > don't wait for that, you could start up the next transaction and have an irq > come in that screws up that transaction. > > It might be sufficient to just wait for the INPUT_DONE_FLAG. That cannot be > signalled unless the rx_bytes == xfer->len. > Right, that should simply it little bit. Regards, Sricharan -- "QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
