[RFC,v5,6/6] i2c: dev: mark RDWR buffers as DMA_SAFE

Message ID 20170920185956.13874-7-wsa+renesas@sang-engineering.com
State New
Headers show
Series
  • i2c: document DMA handling and add helpers for it
Related show

Commit Message

Wolfram Sang Sept. 20, 2017, 6:59 p.m.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/i2c/i2c-dev.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Jonathan Cameron Sept. 21, 2017, 2:17 p.m. | #1
On Wed, 20 Sep 2017 20:59:56 +0200
Wolfram Sang <wsa+renesas@sang-engineering.com> wrote:

> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Makes sense as do the other drivers.

Feel free to add

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

to all of them (though they hardly took a lot of reviewing given how simple
the patches were :)

> ---
>  drivers/i2c/i2c-dev.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
> index 6f638bbc922db4..bbc7aadb4c899d 100644
> --- a/drivers/i2c/i2c-dev.c
> +++ b/drivers/i2c/i2c-dev.c
> @@ -280,6 +280,8 @@ static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client,
>  			res = PTR_ERR(rdwr_pa[i].buf);
>  			break;
>  		}
> +		/* memdup_user allocates with GFP_KERNEL, so DMA is ok */
> +		rdwr_pa[i].flags |= I2C_M_DMA_SAFE;
>  
>  		/*
>  		 * If the message length is received from the slave (similar
Wolfram Sang Sept. 21, 2017, 2:23 p.m. | #2
On Thu, Sep 21, 2017 at 03:17:44PM +0100, Jonathan Cameron wrote:
> On Wed, 20 Sep 2017 20:59:56 +0200
> Wolfram Sang <wsa+renesas@sang-engineering.com> wrote:
> 
> > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> 
> Makes sense as do the other drivers.
> 
> Feel free to add
> 
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> to all of them (though they hardly took a lot of reviewing given how simple
> the patches were :)

Well, bugs can slip in everywhere, so thanks for the review!

Patch

diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index 6f638bbc922db4..bbc7aadb4c899d 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -280,6 +280,8 @@  static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client,
 			res = PTR_ERR(rdwr_pa[i].buf);
 			break;
 		}
+		/* memdup_user allocates with GFP_KERNEL, so DMA is ok */
+		rdwr_pa[i].flags |= I2C_M_DMA_SAFE;
 
 		/*
 		 * If the message length is received from the slave (similar