Patch "spi/rockchip: fix bug that cause the failure to read data in DMA mode" has been added to the 3.17-stable tree

[g***@linuxfoundation.org]

This is a note to let you know that I've just added the patch titled

spi/rockchip: fix bug that cause the failure to read data in DMA mode

to the 3.17-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
spi-rockchip-fix-bug-that-cause-the-failure-to-read-data-in-dma-mode.patch
and it can be found in the queue-3.17 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,

From a24e70c0ac146f8bcae3cdb7f514950d5b32219e Mon Sep 17 00:00:00 2001

From: Addy Ke <***@rock-chips.com>
Date: Thu, 25 Sep 2014 14:59:41 +0800
Subject: spi/rockchip: fix bug that cause the failure to read data in DMA mode

From: Addy Ke <***@rock-chips.com>

commit a24e70c0ac146f8bcae3cdb7f514950d5b32219e upstream.

In my test on RK3288-pinky board, if spi is enabled, it will begin to
read data from slave regardless of whether the DMA is ready. So we
need prepare DMA before spi is enable.

Signed-off-by: Addy Ke <***@rock-chips.com>
Signed-off-by: Mark Brown <***@kernel.org>
Signed-off-by: Greg Kroah-Hartman <***@linuxfoundation.org>

---
drivers/spi/spi-rockchip.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)

--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -415,7 +415,7 @@ static void rockchip_spi_dma_txcb(void *
spin_unlock_irqrestore(&rs->lock, flags);
}

-static int rockchip_spi_dma_transfer(struct rockchip_spi *rs)
+static void rockchip_spi_prepare_dma(struct rockchip_spi *rs)
{
unsigned long flags;
struct dma_slave_config rxconf, txconf;
@@ -474,8 +474,6 @@ static int rockchip_spi_dma_transfer(str
dmaengine_submit(txdesc);
dma_async_issue_pending(rs->dma_tx.ch);
}
-
- return 1;
}

static void rockchip_spi_config(struct rockchip_spi *rs)
@@ -557,16 +555,17 @@ static int rockchip_spi_transfer_one(
else if (rs->rx)
rs->tmode = CR0_XFM_RO;

- if (master->can_dma && master->can_dma(master, spi, xfer))
+ /* we need prepare dma before spi was enabled */
+ if (master->can_dma && master->can_dma(master, spi, xfer)) {
rs->use_dma = 1;
- else
+ rockchip_spi_prepare_dma(rs);
+ } else {
rs->use_dma = 0;
+ }

rockchip_spi_config(rs);

- if (rs->use_dma)
- ret = rockchip_spi_dma_transfer(rs);
- else
+ if (!rs->use_dma)
ret = rockchip_spi_pio_transfer(rs);

return ret;


Patches currently in stable-queue which might be from ***@rock-chips.com are

queue-3.17/spi-rockchip-fix-bug-that-cause-the-failure-to-read-data-in-dma-mode.patch