[3.13.y-ckt stable] Patch "iio: adis16400: Fix burst mode" has been added to staging queue
Kamal Mostafa
kamal at canonical.com
Tue Jul 7 22:16:10 UTC 2015
This is a note to let you know that I have just added a patch titled
iio: adis16400: Fix burst mode
to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree
which can be found at:
http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue
This patch is scheduled to be released in version 3.13.11-ckt23.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
------
>From 1c07bc2d11313e99a5b2e43040bf771dc45eb23d Mon Sep 17 00:00:00 2001
From: Paul Cercueil <paul.cercueil at analog.com>
Date: Fri, 15 May 2015 17:18:37 +0200
Subject: iio: adis16400: Fix burst mode
commit 9df560350c90f3d3909fe653399b3584c9a17b61 upstream.
There are a few issues with the burst mode support. For one we don't setup
the rx buffer, so the buffer will never be filled and all samples will read
as the zero. Furthermore the tx buffer has the wrong type, which means the
driver sends the wrong command and not the right data is returned.
The final issue is that in burst mode all channels are transferred. Hence
the length of the transfer length should be the number of hardware
channels * 2 bytes. Currently the driver uses indio_dev->scan_bytes for
this. But if the timestamp channel is enabled the scan_bytes will be larger
than the burst length. Fix this by just calculating the burst length based
on the number of hardware channels.
Signed-off-by: Paul Cercueil <paul.cercueil at analog.com>
Signed-off-by: Lars-Peter Clausen <lars at metafoo.de>
Fixes: 5eda3550a3cc ("staging:iio:adis16400: Preallocate transfer message")
Signed-off-by: Jonathan Cameron <jic23 at kernel.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
drivers/iio/imu/adis16400_buffer.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/iio/imu/adis16400_buffer.c b/drivers/iio/imu/adis16400_buffer.c
index 6e727ff..629ae84 100644
--- a/drivers/iio/imu/adis16400_buffer.c
+++ b/drivers/iio/imu/adis16400_buffer.c
@@ -18,7 +18,8 @@ int adis16400_update_scan_mode(struct iio_dev *indio_dev,
{
struct adis16400_state *st = iio_priv(indio_dev);
struct adis *adis = &st->adis;
- uint16_t *tx;
+ unsigned int burst_length;
+ u8 *tx;
if (st->variant->flags & ADIS16400_NO_BURST)
return adis_update_scan_mode(indio_dev, scan_mask);
@@ -26,26 +27,27 @@ int adis16400_update_scan_mode(struct iio_dev *indio_dev,
kfree(adis->xfer);
kfree(adis->buffer);
+ /* All but the timestamp channel */
+ burst_length = (indio_dev->num_channels - 1) * sizeof(u16);
+
adis->xfer = kcalloc(2, sizeof(*adis->xfer), GFP_KERNEL);
if (!adis->xfer)
return -ENOMEM;
- adis->buffer = kzalloc(indio_dev->scan_bytes + sizeof(u16),
- GFP_KERNEL);
+ adis->buffer = kzalloc(burst_length + sizeof(u16), GFP_KERNEL);
if (!adis->buffer)
return -ENOMEM;
- tx = adis->buffer + indio_dev->scan_bytes;
-
+ tx = adis->buffer + burst_length;
tx[0] = ADIS_READ_REG(ADIS16400_GLOB_CMD);
tx[1] = 0;
adis->xfer[0].tx_buf = tx;
adis->xfer[0].bits_per_word = 8;
adis->xfer[0].len = 2;
- adis->xfer[1].tx_buf = tx;
+ adis->xfer[1].rx_buf = adis->buffer;
adis->xfer[1].bits_per_word = 8;
- adis->xfer[1].len = indio_dev->scan_bytes;
+ adis->xfer[1].len = burst_length;
spi_message_init(&adis->msg);
spi_message_add_tail(&adis->xfer[0], &adis->msg);
--
1.9.1
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