Re: [PATCH] 2.4.9-ac5: drivers/sound/trident.c

[Alan Cox]

>   
> -	save_flags(flags);
> -	cli();
> +	spin_lock_irqsave(&card->lock, flags);
>  	portDat = cyber_inidx(CYBER_PORT_AUDIO, CYBER_IDX_AUDIO_ENABLE);
>  	/* enable, if it was disabled */
>  	if( (portDat & CYBER_BMSK_AUENZ) != CYBER_BMSK_AUENZ_ENABLE ) {
> @@ -729,7 +730,7 @@
>  		cyber_outidx( CYBER_PORT_AUDIO, 0xb3, 0x06 );
>  		cyber_outidx( CYBER_PORT_AUDIO, 0xbf, 0x00 );
>  	}
> -	restore_flags(flags);
> +	spin_unlock_irqrestore(&card->lock, flags);

This one is wrong. What is probably not obvious on first reading is that
the cyber_out* code actually configures the chipset so needs to be locked
against other chipset configurations (current cli/sti based therefore)

> +			spin_lock_irqsave(&card->lock, flags);
>  			dmabuf->swptr = dmabuf->hwptr = 0;
>  			dmabuf->count = dmabuf->total_bytes = 0;
> +			spin_unlock_irqrestore(&card->lock, flags);
>  		}
>  		if (file->f_mode & FMODE_READ) {
>  			stop_adc(state);
>  			synchronize_irq();
>  			dmabuf->ready = 0;
> +			spin_lock_irqsave(&card->lock, flags);
>  			dmabuf->swptr = dmabuf->hwptr = 0;
>  			dmabuf->count = dmabuf->total_bytes = 0;
> +			spin_unlock_irqrestore(&card->lock, flags);
>  		}

Possibly needed yes. We have however stopped the adc before we read it
and we hold the semaphore so I think its ok on this card