[3.19.y-ckt stable] Patch "spi: imx: Fix small DMA transfers" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    spi: imx: Fix small DMA transfers

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt6.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 2a4f3e23e918af807c39b03289497c25859a963e Mon Sep 17 00:00:00 2001
From: Sascha Hauer <s.hauer at pengutronix.de>
Date: Fri, 24 Jul 2015 15:01:08 +0200
Subject: spi: imx: Fix small DMA transfers

commit f6ee9b582d2db652497b73c1f117591dfb6d3a90 upstream.

DMA transfers must be greater than the watermark level size. spi_imx->rx_wml
and spi_imx->tx_wml contain the watermark level in 32bit words whereas struct
spi_transfer contains the transfer len in bytes. Fix the check if DMA is
possible for a transfer accordingly. This fixes transfers with sizes between
33 and 128 bytes for which previously was claimed that DMA is possible.

Fixes: f62caccd12c17e4 (spi: spi-imx: add DMA support)
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
Signed-off-by: Mark Brown <broonie at kernel.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/spi/spi-imx.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 308c2d3..b9046f7 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -202,8 +202,9 @@ static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
 {
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(master);

-	if (spi_imx->dma_is_inited && (transfer->len > spi_imx->rx_wml)
-	    && (transfer->len > spi_imx->tx_wml))
+	if (spi_imx->dma_is_inited
+	    && transfer->len > spi_imx->rx_wml * sizeof(u32)
+	    && transfer->len > spi_imx->tx_wml * sizeof(u32))
 		return true;
 	return false;
 }
--
1.9.1