Re: My vote against eepro* removal

[Evgeniy Polyakov]

On Fri, Jan 20, 2006 at 11:51:23AM +0100, kus Kusche Klaus (kus@xxxxxxxx) wrote:
> From: Evgeniy Polyakov [mailto:johnpol@xxxxxxxxxxx] 
> > Each MDIO read can take upto 2 msecs (!) and at least 20 
> > usecs in e100,
> > and this runs in timer handler.
> > Concider attaching (only compile tested) patch which moves 
> > e100 watchdog
> > into workqueue.
> 
> Tested the patch. Works and has the expected effects:
> 
> Fully preemptible kernel: 
> No change: 500 us delay at rtprio 1, no delay at higher rtprio.
> (you just moved the 500 us piece of code from one rtprio 1 kernel 
> thread to another rtprio 1 kernel thread).
> 
> Kernel with desktop preemption:
> Originally: Threads at any rtprio suffered from 500 us delay.
> With your patch: Only rtprio 1 threads suffer from 500 us delay,
> no delay at higher rtprio.

Just a hack:

--- drivers/net/e100.c.1	2006-01-20 13:39:19.000000000 +0300
+++ drivers/net/e100.c	2006-01-20 14:15:40.000000000 +0300
@@ -879,8 +879,8 @@
 
 	writel((reg << 16) | (addr << 21) | dir | data, &nic->csr->mdi_ctrl);
 
-	for(i = 0; i < 100; i++) {
-		udelay(20);
+	for(i = 0; i < 1000; i++) {
+		udelay(2);
 		if((data_out = readl(&nic->csr->mdi_ctrl)) & mdi_ready)
 			break;
 	}


> -- 
> Klaus Kusche                 (Software Development - Control Systems)
> KEBA AG             Gewerbepark Urfahr, A-4041 Linz, Austria (Europe)
> Tel: +43 / 732 / 7090-3120                 Fax: +43 / 732 / 7090-6301
> E-Mail: kus@xxxxxxxx                                WWW: www.keba.com
>  

-- 
	Evgeniy Polyakov
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