netdev - Re: [PATCH] Re: still having r8169 woes with XID 18000000

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1275729201.5238.2.camel@edumazet-laptop>
Date:	Sat, 05 Jun 2010 11:13:21 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Timo Teräs <timo.teras@....fi>
Cc:	Phil Sutter <phil@....cc>,
	françois romieu <romieu@...zoreil.com>,
	netdev@...r.kernel.org
Subject: Re: [PATCH] Re: still having r8169 woes with XID 18000000

Le samedi 05 juin 2010 à 10:39 +0300, Timo Teräs a écrit :

> Ok, I compared Realtek's and the in-tree driver. The only essential
> difference is that Realtek driver uses udelay(100) in mdio_write()'s
> busy polling loop where as the in-tree uses udelay(25). And that seems
> to be the magic difference! Using udelay(100) fixes this!
> 
> I'm guessing that the phy needs slight delay between consecutive
> mdio_write's even if it has advertised that the write has been
> completed. And yes, just adding a small delay in the end of mdio_write
> does seem to work too.
> 
> Francois, you think the below patch is ok? Should I send it as properly
> formatted commit?
> 
> diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c
> index 217e709..6db62bf 100644
> --- a/drivers/net/r8169.c
> +++ b/drivers/net/r8169.c
> @@ -559,6 +559,7 @@ static void mdio_write(void __iomem *ioaddr,
>  			break;
>  		udelay(25);
>  	}
> +	udelay(25);
>  }
> 
>  static int mdio_read(void __iomem *ioaddr, int reg_addr)
> --

Sure this deserves an official patch with all prereqs, but please add a
comment in mdio_write() why this extra udelay(25) is needed, especially
since you say of udelay(100) 'fixes the bug'.



--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html