[PATCH] DMA: shdma: fix CHCLR register address calculation

From: Guennadi Liakhovetski
Date: Tue Jul 02 2013 - 11:38:14 EST


struct sh_dmae_device::chan_reg is a pointer to u32, therefore when adding
offsets to it care should be taken to add offsets in sizeof(u32) units, not
in bytes. This patch corrects such a bug. While at it we also remove the
redundant parameter of the affected function.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@xxxxxxxxx>
---

This is a theoretical fix, I don't have a test-case for it, but the
original calculation does seem to be buggy to me. Reviews and tests are
welcome.

drivers/dma/sh/shdma.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/sh/shdma.c b/drivers/dma/sh/shdma.c
index 98b2693..c7950be 100644
--- a/drivers/dma/sh/shdma.c
+++ b/drivers/dma/sh/shdma.c
@@ -51,12 +51,12 @@
static DEFINE_SPINLOCK(sh_dmae_lock);
static LIST_HEAD(sh_dmae_devices);

-static void chclr_write(struct sh_dmae_chan *sh_dc, u32 data)
+static void channel_clear(struct sh_dmae_chan *sh_dc)
{
struct sh_dmae_device *shdev = to_sh_dev(sh_dc);

- __raw_writel(data, shdev->chan_reg +
- shdev->pdata->channel[sh_dc->shdma_chan.id].chclr_offset);
+ __raw_writel(0, shdev->chan_reg +
+ shdev->pdata->channel[sh_dc->shdma_chan.id].chclr_offset / sizeof(u32));
}

static void sh_dmae_writel(struct sh_dmae_chan *sh_dc, u32 data, u32 reg)
@@ -135,7 +135,7 @@ static int sh_dmae_rst(struct sh_dmae_device *shdev)
for (i = 0; i < shdev->pdata->channel_num; i++) {
struct sh_dmae_chan *sh_chan = shdev->chan[i];
if (sh_chan)
- chclr_write(sh_chan, 0);
+ channel_clear(sh_chan);
}
}

--
1.7.2.5

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