On Wed, 2018-08-08 at 22:57 +0200, Wolfram Sang wrote:

On Sat, Jul 07, 2018 at 05:29:54PM +0800, Jun Gao wrote:

quoted

From: Jun Gao <redacted>

This function is needed by i2c_get_dma_safe_msg_buf() potentially.
It is used to free DMA safe buffer when DMA operation fails.

Signed-off-by: Jun Gao <redacted>

Right, we need something like this. This leaks in the sh_mobile driver,
too :(

I am still thinking if there is a nice way to put this functionality
into i2c_release_dma_safe_msg_buf() itself somehow...

Wolfram,

I have second thought on these API now. Recently, we have saw similar
issue for spi device driver.

I believe the reason for these api is because some arch changed to can
not do DMA on stack recently. Maybe we should have dma_mapping to bounce
buffer like it bounce un-dma-able address for those arch? or we should
have a common driver API for this, not just for i2c?

Joe.C