linux-kernel - Re: [PATCH v2 1/2] dmaengine: dw-edma: Fix unmasking STOP and ABORT interrupts for HDMA

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Message-ID: <dnvoktjxx2m5oy2m5ocrgyd4veypnjbjnth364hl32ou4gm3t2@tjxrsowsabgr>
Date: Fri, 2 Aug 2024 02:42:09 +0300
From: Serge Semin <fancer.lancer@...il.com>
To: Mrinmay Sarkar <quic_msarkar@...cinc.com>
Cc: manivannan.sadhasivam@...aro.org, vkoul@...nel.org, 
	quic_shazhuss@...cinc.com, quic_nitegupt@...cinc.com, quic_ramkri@...cinc.com, 
	quic_nayiluri@...cinc.com, quic_krichai@...cinc.com, quic_vbadigan@...cinc.com, 
	stable@...r.kernel.org, Cai Huoqing <cai.huoqing@...ux.dev>, dmaengine@...r.kernel.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 1/2] dmaengine: dw-edma: Fix unmasking STOP and ABORT
 interrupts for HDMA

On Tue, Jul 23, 2024 at 06:49:31PM +0530, Mrinmay Sarkar wrote:
> The current logic is enabling both STOP_INT_MASK and ABORT_INT_MASK
> bit. This is apparently masking those particular interrupts rather than
> unmasking the same. If the interrupts are masked, they would never get
> triggered.
> 
> So fix the issue by unmasking the STOP and ABORT interrupts properly.
> 
> Fixes: e74c39573d35 ("dmaengine: dw-edma: Add support for native HDMA")
> cc: stable@...r.kernel.org
> Signed-off-by: Mrinmay Sarkar <quic_msarkar@...cinc.com>
> ---
>  drivers/dma/dw-edma/dw-hdma-v0-core.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/dma/dw-edma/dw-hdma-v0-core.c b/drivers/dma/dw-edma/dw-hdma-v0-core.c
> index 10e8f07..fa89b3a 100644
> --- a/drivers/dma/dw-edma/dw-hdma-v0-core.c
> +++ b/drivers/dma/dw-edma/dw-hdma-v0-core.c
> @@ -247,10 +247,11 @@ static void dw_hdma_v0_core_start(struct dw_edma_chunk *chunk, bool first)
>  	if (first) {
>  		/* Enable engine */
>  		SET_CH_32(dw, chan->dir, chan->id, ch_en, BIT(0));
> -		/* Interrupt enable&unmask - done, abort */
> -		tmp = GET_CH_32(dw, chan->dir, chan->id, int_setup) |
> -		      HDMA_V0_STOP_INT_MASK | HDMA_V0_ABORT_INT_MASK |
> -		      HDMA_V0_LOCAL_STOP_INT_EN | HDMA_V0_LOCAL_ABORT_INT_EN;

Just curious, if all the interrupts were actually masked, how has this
been even working?.. In other words if it affected both local and
remote interrupts, then the HDMA driver has never actually worked,
right?

> +		/* Interrupt unmask - STOP, ABORT */

> +		tmp = GET_CH_32(dw, chan->dir, chan->id, int_setup) &
> +		      ~HDMA_V0_STOP_INT_MASK & ~HDMA_V0_ABORT_INT_MASK;

Please convert this to:
+		/* Interrupt unmask - stop, abort */
+		tmp = GET_CH_32(dw, chan->dir, chan->id, int_setup);
+		tmp &= ~(HDMA_V0_STOP_INT_MASK | HDMA_V0_ABORT_INT_MASK);

-Serge(y)

> +		/* Interrupt enable - STOP, ABORT */
> +		tmp |= HDMA_V0_LOCAL_STOP_INT_EN | HDMA_V0_LOCAL_ABORT_INT_EN;
>  		if (!(dw->chip->flags & DW_EDMA_CHIP_LOCAL))
>  			tmp |= HDMA_V0_REMOTE_STOP_INT_EN | HDMA_V0_REMOTE_ABORT_INT_EN;
>  		SET_CH_32(dw, chan->dir, chan->id, int_setup, tmp);
> -- 
> 2.7.4
>