From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935517AbbGHPvn (ORCPT ); Wed, 8 Jul 2015 11:51:43 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:47913 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758869AbbGHPlH (ORCPT ); Wed, 8 Jul 2015 11:41:07 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Paul Cercueil , Lars-Peter Clausen , Jonathan Cameron , Kamal Mostafa Subject: [PATCH 3.13.y-ckt 23/56] iio: adis16400: Fix burst mode Date: Wed, 8 Jul 2015 08:40:04 -0700 Message-Id: <1436370037-25874-24-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1436370037-25874-1-git-send-email-kamal@canonical.com> References: <1436370037-25874-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.13 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13.11-ckt23 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Paul Cercueil 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 Signed-off-by: Lars-Peter Clausen Fixes: 5eda3550a3cc ("staging:iio:adis16400: Preallocate transfer message") Signed-off-by: Jonathan Cameron Signed-off-by: Kamal Mostafa --- 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