On Mon, Nov 13, 2017 at 09:05:40PM +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@xxxxxxxxxx>
Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx>
> ---
> drivers/mfd/cros_ec_spi.c | 25 +++++++++----------------
> 1 file changed, 9 insertions(+), 16 deletions(-)
>
> 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)
> --
> 2.7.4
>
--
To unsubscribe from this list: send the line "unsubscribe linux-tegra" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
