On Mon, Jun 12, 2017 at 6:42 AM, Song liwei <liwei.song@xxxxxxxxxxxxx> wrote:
> From: Liwei Song <liwei.song@xxxxxxxxxxxxx>
>
> Fix the following calltrace:
No, you don't fix a call trace, you are fixing a bug.
> This happen When run "i2cdetect -y 0" detect SMBus iSMT adapter.
>
> After finished I2C block read/write, when unmap the data buffer,
> a wrong device address was pass to dma_unmap_single(),
> the right
> device address should be "dev" not "&adap->dev", the relation is
> *(&adap->dev) == dev.
This is confusing. You are telling that there are two copies of struct
device here?
Otherwise if one is a pointer to the real struct device, there
shouldn't be a problem.
> When come into Intel IOMMU routine, the wrong
> devices address was operated.
This basically duplicates what you have said previously.
> To fix this, give dma_unmap_single() the "dev" parameter, just like
> what dma_map_single() does, then unmap can find the right devices.
Fix per se looks good, explanation is confusing.
>
> Signed-off-by: Liwei Song <liwei.song@xxxxxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-ismt.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-ismt.c b/drivers/i2c/busses/i2c-ismt.c
> index 1db3e0d..605d44e 100644
> --- a/drivers/i2c/busses/i2c-ismt.c
> +++ b/drivers/i2c/busses/i2c-ismt.c
> @@ -585,7 +585,7 @@ static int ismt_access(struct i2c_adapter *adap, u16 addr,
>
> /* unmap the data buffer */
> if (dma_size != 0)
> - dma_unmap_single(&adap->dev, dma_addr, dma_size, dma_direction);
> + dma_unmap_single(dev, dma_addr, dma_size, dma_direction);
>
> if (unlikely(!time_left)) {
> dev_err(dev, "completion wait timed out\n");
> --
> 2.7.4
>
--
With Best Regards,
Andy Shevchenko
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