Re: [PATCH v3 07/16] mtd: rawnand: qcom: wait for desc completion in all BAM channels

[Miquel Raynal <miquel.raynal@bootlin.com>]

Hi Abhishek,

On Fri, 25 May 2018 17:51:35 +0530, Abhishek Sahu
<absahu@codeaurora.org> wrote:

> The BAM has 3 channels - tx, rx and command. command channel
> is used for register read/writes, tx channel for data writes
> and rx channel for data reads. Currently, the driver assumes the
> transfer completion once it gets all the command descriptors
> completed. Sometimes, there is race condition between data channel
> (tx/rx) and command channel completion. In these cases,
> the data present in buffer is not valid during small window
> between command descriptor completion and data descriptor
> completion.
> 
> This patch generates NAND transfer completion when both
> (Data and Command) DMA channels have completed all its DMA
> descriptors. It assigns completion callback in last
> DMA descriptors of that channel and wait for completion.
> 
> Fixes: 8d6b6d7e135e ("mtd: nand: qcom: support for command descriptor formation")
> Cc: stable@vger.kernel.org
> Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
> ---
> * Changes from v2:
>   1. Changed commit message and comments slightly
>   2. Renamed wait_second_completion from first_chan_done and set
>      it before submit desc
>   3. Mark for stable tree
> 
> * Changes from v1:
>   NONE
> 
>  drivers/mtd/nand/raw/qcom_nandc.c | 53 ++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 52 insertions(+), 1 deletion(-)
> 

Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>