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Subject: Re: [PATCH v2] dmaengine: ioat setting ioat timeout as module
 parameter
To:     leonid.ravich@dell.com, dmaengine@vger.kernel.org
Cc:     lravich@gmail.com, Dan Williams <dan.j.williams@intel.com>,
        Vinod Koul <vkoul@kernel.org>,
        "Alexander.Barabash@dell.com" <Alexander.Barabash@dell.com>,
        linux-kernel@vger.kernel.org
References: <20200701140849.8828-1-leonid.ravich@dell.com>
 <20200701184816.29138-1-leonid.ravich@dell.com>
From:   Dave Jiang <dave.jiang@intel.com>
Message-ID: <5c19ef4f-21ce-04ec-0ea9-685a1885a50a@intel.com>
Date:   Wed, 1 Jul 2020 12:04:38 -0700
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On 7/1/2020 11:48 AM, leonid.ravich@dell.com wrote:
> From: Leonid Ravich <Leonid.Ravich@emc.com>
> 
> DMA transaction time to completion  is a function of
> PCI bandwidth,transaction size and a queue depth.
> So hard coded value for timeouts might be wrong
> for some scenarios.
> 
> Signed-off-by: Leonid Ravich <Leonid.Ravich@emc.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
> Changing in v2
>    - misspelling of completion
>   drivers/dma/ioat/dma.c | 12 ++++++++++++
>   drivers/dma/ioat/dma.h |  2 --
>   2 files changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
> index 8ad0ad861c86..fd782aee02d9 100644
> --- a/drivers/dma/ioat/dma.c
> +++ b/drivers/dma/ioat/dma.c
> @@ -26,6 +26,18 @@
>   
>   #include "../dmaengine.h"
>   
> +int completion_timeout = 200;
> +module_param(completion_timeout, int, 0644);
> +MODULE_PARM_DESC(completion_timeout,
> +		"set ioat completion timeout [msec] (default 200 [msec])");
> +int idle_timeout = 2000;
> +module_param(idle_timeout, int, 0644);
> +MODULE_PARM_DESC(idle_timeout,
> +		"set ioat idel timeout [msec] (default 2000 [msec])");
> +
> +#define IDLE_TIMEOUT msecs_to_jiffies(idle_timeout)
> +#define COMPLETION_TIMEOUT msecs_to_jiffies(completion_timeout)
> +
>   static char *chanerr_str[] = {
>   	"DMA Transfer Source Address Error",
>   	"DMA Transfer Destination Address Error",
> diff --git a/drivers/dma/ioat/dma.h b/drivers/dma/ioat/dma.h
> index e6b622e1ba92..f7f31fdf14cf 100644
> --- a/drivers/dma/ioat/dma.h
> +++ b/drivers/dma/ioat/dma.h
> @@ -104,8 +104,6 @@ struct ioatdma_chan {
>   	#define IOAT_RUN 5
>   	#define IOAT_CHAN_ACTIVE 6
>   	struct timer_list timer;
> -	#define COMPLETION_TIMEOUT msecs_to_jiffies(100)
> -	#define IDLE_TIMEOUT msecs_to_jiffies(2000)
>   	#define RESET_DELAY msecs_to_jiffies(100)
>   	struct ioatdma_device *ioat_dma;
>   	dma_addr_t completion_dma;
>