diff options
| author | Vladimir Oltean <olteanv@gmail.com> | 2019-12-27 03:24:17 +0200 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2019-12-27 23:03:43 +0000 |
| commit | 862dd2a946aa1417f013fb748e2aa0f4349b405b (patch) | |
| tree | 8710c9f5a8d6899b3f0d9e931fa7a43b2898e2dd /drivers/spi/spi.c | |
| parent | 9cd34efbd3012171c102910ce17ee632a3cccb44 (diff) | |
spi: Don't look at TX buffer for PTP system timestamping
The API for PTP system timestamping (associating a SPI transaction with
the system time at which it was transferred) is flawed: it assumes that
the xfer->tx_buf pointer will always be present.
This is, of course, not always the case.
So introduce a "progress" variable that denotes how many word have been
transferred.
Fix the Freescale DSPI driver, the only user of the API so far, in the
same patch.
Fixes: b42faeee718c ("spi: Add a PTP system timestamp to the transfer structure")
Fixes: d6b71dfaeeba ("spi: spi-fsl-dspi: Implement the PTP system timestamping for TCFQ mode")
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Link: https://lore.kernel.org/r/20191227012417.1057-1-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi.c')
| -rw-r--r-- | drivers/spi/spi.c | 22 |
1 files changed, 8 insertions, 14 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 0d40953b463c..6b95cd957ba7 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1499,8 +1499,7 @@ static void spi_pump_messages(struct kthread_work *work) * advances its @tx buffer pointer monotonically. * @ctlr: Pointer to the spi_controller structure of the driver * @xfer: Pointer to the transfer being timestamped - * @tx: Pointer to the current word within the xfer->tx_buf that the driver is - * preparing to transmit right now. + * @progress: How many words (not bytes) have been transferred so far * @irqs_off: If true, will disable IRQs and preemption for the duration of the * transfer, for less jitter in time measurement. Only compatible * with PIO drivers. If true, must follow up with @@ -1510,21 +1509,19 @@ static void spi_pump_messages(struct kthread_work *work) */ void spi_take_timestamp_pre(struct spi_controller *ctlr, struct spi_transfer *xfer, - const void *tx, bool irqs_off) + size_t progress, bool irqs_off) { - u8 bytes_per_word = DIV_ROUND_UP(xfer->bits_per_word, 8); - if (!xfer->ptp_sts) return; if (xfer->timestamped_pre) return; - if (tx < (xfer->tx_buf + xfer->ptp_sts_word_pre * bytes_per_word)) + if (progress < xfer->ptp_sts_word_pre) return; /* Capture the resolution of the timestamp */ - xfer->ptp_sts_word_pre = (tx - xfer->tx_buf) / bytes_per_word; + xfer->ptp_sts_word_pre = progress; xfer->timestamped_pre = true; @@ -1546,23 +1543,20 @@ EXPORT_SYMBOL_GPL(spi_take_timestamp_pre); * timestamped. * @ctlr: Pointer to the spi_controller structure of the driver * @xfer: Pointer to the transfer being timestamped - * @tx: Pointer to the current word within the xfer->tx_buf that the driver has - * just transmitted. + * @progress: How many words (not bytes) have been transferred so far * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU. */ void spi_take_timestamp_post(struct spi_controller *ctlr, struct spi_transfer *xfer, - const void *tx, bool irqs_off) + size_t progress, bool irqs_off) { - u8 bytes_per_word = DIV_ROUND_UP(xfer->bits_per_word, 8); - if (!xfer->ptp_sts) return; if (xfer->timestamped_post) return; - if (tx < (xfer->tx_buf + xfer->ptp_sts_word_post * bytes_per_word)) + if (progress < xfer->ptp_sts_word_post) return; ptp_read_system_postts(xfer->ptp_sts); @@ -1573,7 +1567,7 @@ void spi_take_timestamp_post(struct spi_controller *ctlr, } /* Capture the resolution of the timestamp */ - xfer->ptp_sts_word_post = (tx - xfer->tx_buf) / bytes_per_word; + xfer->ptp_sts_word_post = progress; xfer->timestamped_post = true; } |