Subject: [PATCH] at_hdmac: bugfix for enabling channel irq

From: [email-masked] (Nicolas Ferre)
Date: Tue, 17 Jan 2012 16:28:20 +0100

On 01/17/2012 10:28 AM, Nikolaus Voss :
> commit 463894705e4089d0ff69e7d877312d496ac70e5b deleted redundant
> chan_id and chancnt initialization in dma drivers as this is done
> in dma_async_device_register().
> 
> However, atc_enable_irq() relied on chan_id set before registering
> the device, what left only channel 0 functional for this driver.
> 
> This patch introduces atc_enable/disable_chan_irq() as a variant
> of atc_enable/disable_irq() with the channel as explicit argument.
> 
> Signed-off-by: Nikolaus Voss <[email-masked]>

Signed-off-by: Nicolas Ferre <[email-masked]>
Cc: stable <[email-masked]>

Vinod, can you please queue it in a "fixes" branch for 3.3. The stable
tag is needed to address errors in 3.2 kernel series.

Nikolaus, thanks for your fix.

Best regards,

> ---
>  drivers/dma/at_hdmac.c      |    4 ++--
>  drivers/dma/at_hdmac_regs.h |   17 ++++++++---------
>  2 files changed, 10 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index fcfa0a8..a60adbf 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -1286,7 +1286,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
>  
>  		tasklet_init(&atchan->tasklet, atc_tasklet,
>  				(unsigned long)atchan);
> -		atc_enable_irq(atchan);
> +		atc_enable_chan_irq(atdma, i);
>  	}
>  
>  	/* set base routines */
> @@ -1353,7 +1353,7 @@ static int __exit at_dma_remove(struct platform_device *pdev)
>  		struct at_dma_chan	*atchan = to_at_dma_chan(chan);
>  
>  		/* Disable interrupts */
> -		atc_disable_irq(atchan);
> +		atc_disable_chan_irq(atdma, chan->chan_id);
>  		tasklet_disable(&atchan->tasklet);
>  
>  		tasklet_kill(&atchan->tasklet);
> diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h
> index aa4c9ae..5aa82b4 100644
> --- a/drivers/dma/at_hdmac_regs.h
> +++ b/drivers/dma/at_hdmac_regs.h
> @@ -326,28 +326,27 @@ static void atc_dump_lli(struct at_dma_chan *atchan, struct at_lli *lli)
>  }
>  
>  
> -static void atc_setup_irq(struct at_dma_chan *atchan, int on)
> +static void atc_setup_irq(struct at_dma *atdma, int chan_id, int on)
>  {
> -	struct at_dma	*atdma = to_at_dma(atchan->chan_common.device);
> -	u32		ebci;
> +	u32 ebci;
>  
>  	/* enable interrupts on buffer transfer completion & error */
> -	ebci =    AT_DMA_BTC(atchan->chan_common.chan_id)
> -		| AT_DMA_ERR(atchan->chan_common.chan_id);
> +	ebci =    AT_DMA_BTC(chan_id)
> +		| AT_DMA_ERR(chan_id);
>  	if (on)
>  		dma_writel(atdma, EBCIER, ebci);
>  	else
>  		dma_writel(atdma, EBCIDR, ebci);
>  }
>  
> -static inline void atc_enable_irq(struct at_dma_chan *atchan)
> +static void atc_enable_chan_irq(struct at_dma *atdma, int chan_id)
>  {
> -	atc_setup_irq(atchan, 1);
> +	atc_setup_irq(atdma, chan_id, 1);
>  }
>  
> -static inline void atc_disable_irq(struct at_dma_chan *atchan)
> +static void atc_disable_chan_irq(struct at_dma *atdma, int chan_id)
>  {
> -	atc_setup_irq(atchan, 0);
> +	atc_setup_irq(atdma, chan_id, 0);
>  }
>  
>  

-- 
Nicolas Ferre