[Prism54-devel] suggestion to shorten interrupt code path

[Bruno Randolf]

hi rainer!

oh, yes! i am! :)

i'm currently trying to solve exactly that problem... i tried to use tasklets 
for the mgmt queue handling, but it does not work yet...

please,
bruno

On Thursday 21 April 2005 23:00, Rainer Weikusat wrote:
> I happen to have the mispleasure to get this driver
> to actually work (for Indigo, AFAIK, and on ARM)[*], and I have
> replaced the interrupt handler code today. Before I did this,
> I used to have packet loss rates > 80% when flood pinging, and now
> they have dropped to zero (I still do not really believe this :-).
> The code I am using at present (2.4 only) looks basically like this:
>
> void
> islpci_interrupt(int irq, void *arg, struct pt_regs *regs)
> {
> 	islpci_private *priv;
> 	u32 irqs, saved_irqs;
>
> 	priv = arg;
> 	spin_lock(&priv->slock);
>
> 	irqs = check_and_acknowledge_irqs(priv->device_base);
> 	if (!irqs) goto out;
>
> 	p_trace(("indigo: irqs 0x%08x, state %u\n", irqs, priv->state));
> 	saved_irqs = irqs;
>
> 	irqs &= ~INDIGO_FROM_IRQ_UPDATE;
> 	if (irqs != saved_irqs) {
> 		handle_update(priv);
>
> 		saved_irqs = irqs; /* could use MOVS on arm if gcc could */
> 		if (!saved_irqs) goto out;
> 	}
>
> 	irqs &= ~INDIGO_FROM_IRQ_DID_WAKEUP;
> 	if (irqs != saved_irqs) {
> 		handle_wakeup(priv);
>
> 		saved_irqs = irqs;
> 		if (!saved_irqs) goto out;
> 	}
>
> 	irqs &= ~INDIGO_FROM_IRQ_INIT;
> 	if (irqs != saved_irqs) {
> 		handle_init(priv);
>
> 		saved_irqs = irqs;
> 		if (!saved_irqs) goto out;
> 	}
>
> 	irqs &= ~INDIGO_FROM_IRQ_WANT_SLEEP;
> 	if (irqs != saved_irqs) handle_sleep(priv);
>
>  out:
> 	spin_unlock(&priv->slock);
> }
>
> - just in case someone is interested -
>
> [*] for instance, I happen to know one cause of 'mgmt timeouts'
>     (device bug, sometimes asserts update but doesn't send data
>      => little endian frame length converted to little endian
>      a 2nd time => kmalloc failure in mgt_receive)
>
>
> _______________________________________________
> Prism54-devel mailing list
> Prism54-devel at prism54.org
> http://prism54.org/mailman/listinfo/prism54-devel
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