Message ID | 1510670608-19594-2-git-send-email-jonathanh@nvidia.com |
---|---|
State | Deferred |
Headers | show |
Series | [V2,1/2] mfd: cros ec: spi: Don't send first message too soon | expand |
Hi, On Tue, Nov 14, 2017 at 6:43 AM, Jon Hunter <jonathanh@nvidia.com> wrote: > The EC SPI driver prevents SPI transfers being to rapidly by keeping > track of the time the last transfer was issued via the > 'last_transfer_ns' variable. Previously, if the 'last_transfer_ns' > variable was zero, this indicated that no previous transfer had been > sent and that no delay was needed. However, the EC SPI driver has > been updated to always initialise the 'last_transfer_ns' variable > during probe and therefore, it is no longer necessary to test if it > is zero. Remove the code that checks if this variable is zero. > > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> > Reviewed-by: Brian Norris <briannorris@chromium.org> > --- > Changes since V1: > - Added Brian's reviewed-by. > > drivers/mfd/cros_ec_spi.c | 25 +++++++++---------------- > 1 file changed, 9 insertions(+), 16 deletions(-) Reviewed-by: Douglas Anderson <dianders@chromium.org> -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Jon, On Tue, Nov 14, 2017 at 02:43:28PM +0000, Jon Hunter wrote: > The EC SPI driver prevents SPI transfers being to rapidly by keeping > track of the time the last transfer was issued via the > 'last_transfer_ns' variable. Previously, if the 'last_transfer_ns' > variable was zero, this indicated that no previous transfer had been > sent and that no delay was needed. However, the EC SPI driver has > been updated to always initialise the 'last_transfer_ns' variable > during probe and therefore, it is no longer necessary to test if it > is zero. Remove the code that checks if this variable is zero. > > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> > Reviewed-by: Brian Norris <briannorris@chromium.org> Acked-by: Benson Leung <bleung@chromium.org>
diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c index a14196e95e9b..7849d781c6bb 100644 --- a/drivers/mfd/cros_ec_spi.c +++ b/drivers/mfd/cros_ec_spi.c @@ -72,8 +72,7 @@ * struct cros_ec_spi - information about a SPI-connected EC * * @spi: SPI device we are connected to - * @last_transfer_ns: time that we last finished a transfer, or 0 if there - * if no record + * @last_transfer_ns: time that we last finished a transfer. * @start_of_msg_delay: used to set the delay_usecs on the spi_transfer that * is sent when we want to turn on CS at the start of a transaction. * @end_of_msg_delay: used to set the delay_usecs on the spi_transfer that @@ -378,18 +377,15 @@ static int cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev, u8 *rx_buf; u8 sum; int ret = 0, final_ret; + unsigned long delay; len = cros_ec_prepare_tx(ec_dev, ec_msg); dev_dbg(ec_dev->dev, "prepared, len=%d\n", len); /* If it's too soon to do another transaction, wait */ - if (ec_spi->last_transfer_ns) { - unsigned long delay; /* The delay completed so far */ - - delay = ktime_get_ns() - ec_spi->last_transfer_ns; - if (delay < EC_SPI_RECOVERY_TIME_NS) - ndelay(EC_SPI_RECOVERY_TIME_NS - delay); - } + delay = ktime_get_ns() - ec_spi->last_transfer_ns; + if (delay < EC_SPI_RECOVERY_TIME_NS) + ndelay(EC_SPI_RECOVERY_TIME_NS - delay); rx_buf = kzalloc(len, GFP_KERNEL); if (!rx_buf) @@ -510,18 +506,15 @@ static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev, u8 *rx_buf; int sum; int ret = 0, final_ret; + unsigned long delay; len = cros_ec_prepare_tx(ec_dev, ec_msg); dev_dbg(ec_dev->dev, "prepared, len=%d\n", len); /* If it's too soon to do another transaction, wait */ - if (ec_spi->last_transfer_ns) { - unsigned long delay; /* The delay completed so far */ - - delay = ktime_get_ns() - ec_spi->last_transfer_ns; - if (delay < EC_SPI_RECOVERY_TIME_NS) - ndelay(EC_SPI_RECOVERY_TIME_NS - delay); - } + delay = ktime_get_ns() - ec_spi->last_transfer_ns; + if (delay < EC_SPI_RECOVERY_TIME_NS) + ndelay(EC_SPI_RECOVERY_TIME_NS - delay); rx_buf = kzalloc(len, GFP_KERNEL); if (!rx_buf)