Subject: Re: [PATCH 1/2 v2] KS8695: fix ks8695_rx_irq() bug.

From: "Figo.zhang" <[email-masked]>
Date: Fri, 13 Nov 2009 00:24:48 +0800

On Mon, 2009-11-16 at 22:58 +0800, zeal wrote:
> From: zeal <[email-masked]>
> 
> Sorry for the previously patches. THEY'RE NOT RIGHT. It's my mistake.
> Please forgive my noise.
> Please review the following patches and ignore the last (v1).
> 
> ks8695 rx irq is edge-level. Before arriving at irq handler, the
> corresponding status bit has been clear(irq's ack).
> So we should not check it after that.

see <KS8695X Integrated Multi-Port Gateway Solution Register
Description> Version 1.00

Interrupt Status Register(INTST Offset 0xE208)

it has said: This edge-triggered interrupt status is cleared by writting
1 , so we should write 1 to clear status bit manually.

> 
> Signed-off-by: zeal <[email-masked]>
> ---
>  drivers/net/arm/ks8695net.c |   22 +++++++---------------
>  1 files changed, 7 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/net/arm/ks8695net.c b/drivers/net/arm/ks8695net.c
> index 0073d19..e15451a 100644
> --- a/drivers/net/arm/ks8695net.c
> +++ b/drivers/net/arm/ks8695net.c
> @@ -433,24 +433,16 @@ ks8695_rx_irq(int irq, void *dev_id)
>  {
>  	struct net_device *ndev = (struct net_device *)dev_id;
>  	struct ks8695_priv *ksp = netdev_priv(ndev);
> -	unsigned long status;
> -
> -	unsigned long mask_bit = 1 << ks8695_get_rx_enable_bit(ksp);
>  
>  	spin_lock(&ksp->rx_lock);
>  
> -	status = readl(KS8695_IRQ_VA + KS8695_INTST);
> -
> -	/*clean rx status bit*/
> -	writel(status | mask_bit , KS8695_IRQ_VA + KS8695_INTST);
> -
> -	if (status & mask_bit) {
> -		if (napi_schedule_prep(&ksp->napi)) {
> -			/*disable rx interrupt*/
> -			status &= ~mask_bit;
> -			writel(status , KS8695_IRQ_VA + KS8695_INTEN);
> -			__napi_schedule(&ksp->napi);
> -		}
> +	if (napi_schedule_prep(&ksp->napi)) {
> +		unsigned long status = readl(KS8695_IRQ_VA + KS8695_INTEN);
> +		unsigned long mask_bit = 1 << ks8695_get_rx_enable_bit(ksp);
> +		/*disable rx interrupt*/
> +		status &= ~mask_bit;
> +		writel(status , KS8695_IRQ_VA + KS8695_INTEN);
> +		__napi_schedule(&ksp->napi);
>  	}
>  
>  	spin_unlock(&ksp->rx_lock);