netdev - Re: [PATCH V2] net: phy: tja11xx: Add IRQ support to the driver

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]

Date:   Thu, 30 May 2019 01:29:30 +0200
From:   Andrew Lunn <andrew@...n.ch>
To:     Marek Vasut <marex@...x.de>
Cc:     Heiner Kallweit <hkallweit1@...il.com>, netdev@...r.kernel.org,
        Florian Fainelli <f.fainelli@...il.com>,
        Guenter Roeck <linux@...ck-us.net>,
        Jean Delvare <jdelvare@...e.com>, linux-hwmon@...r.kernel.org
Subject: Re: [PATCH V2] net: phy: tja11xx: Add IRQ support to the driver

On Tue, May 28, 2019 at 11:33:33PM +0200, Marek Vasut wrote:
> On 5/28/19 11:22 PM, Andrew Lunn wrote:
> >> The link detection on the TJA1100 (not TJA1101) seems unstable at best,
> >> so I better use all the interrupt sources to nudge the PHY subsystem and
> >> have it check the link change.
> > 
> > Then it sounds like you should just ignore interrupts and stay will
> > polling for the TJA1100.
> 
> Polling for the link status change is slow(er) than the IRQ driven
> operation, so I would much rather use the interrupts.

I agree about the speed, but it seems like interrupts on this PHY are
not so reliable. Polling always works. But unfortunately, you cannot
have both interrupts and polling to fix up problems when interrupts
fail. Your call, do you think interrupts really do work?

If you say that tja1101 works as expected, then please just use the
link up/down bits for it.

     Andrew