| Message ID | 1510607140-30582-2-git-send-email-jonathanh@nvidia.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | [1/2] mfd: cros ec: spi: Don't send first message too soon | expand |
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@nvidia.com> Reviewed-by: Brian Norris <briannorris@chromium.org> > --- > 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@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, 13 Nov 2017, 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> > --- > drivers/mfd/cros_ec_spi.c | 25 +++++++++---------------- > 1 file changed, 9 insertions(+), 16 deletions(-) Applied, thanks.
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)
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> --- drivers/mfd/cros_ec_spi.c | 25 +++++++++---------------- 1 file changed, 9 insertions(+), 16 deletions(-)