On Wed, 2007-04-25 at 18:09 +0300, Petko Manolov wrote: > On Wed, 25 Apr 2007, Dan Williams wrote: > > > On Wed, 2007-04-25 at 17:58 +0300, Petko Manolov wrote: > >> In general i agree with the reasoning below. However, isn't it better to > >> remove the code that sets carrier on/off in intr_callback()? > > > > I'm fine with this; whatever makes carrier status work makes me happy :) > > Great. Are you going to submit the new patch or this hard labor will lay > on my shoulders? :)
Well, it looked like you already had one; but if you'd like I'll whip up a new one. Dan > > Petko > > > > >> There's a reliable way of getting the link status by reading the MII. > >> After correct checking of the return value from read_mii_word(), > >> set_carrier() is what is good enough. If 2 seconds is too long of an > >> interval we could reduce it to 1 second or, if needed, less. > >> > >> I'd like to avoid adding additional flags per device as it will take > >> forever to collect information about their "correct" behavior and update > >> pegasus.h. In short i think this part of your patch should be enough: > >> > >> --- > >> > >> @@ -847,10 +848,16 @@ static void intr_callback(struct urb *urb) > >> * d[0].NO_CARRIER kicks in only with failed TX. > >> * ... so monitoring with MII may be safest. > >> */ > >> - if (d[0] & NO_CARRIER) > >> - netif_carrier_off(net); > >> - else > >> - netif_carrier_on(net); > >> - > >> /* bytes 3-4 == rx_lostpkt, reg 2E/2F */ > >> pegasus->stats.rx_missed_errors += ((d[3] & 0x7f) << 8) | d[4]; > >> @@ -950,7 +957,7 @@ static void set_carrier(struct net_device *net) > >> pegasus_t *pegasus = netdev_priv(net); > >> u16 tmp; > >> > >> - if (!read_mii_word(pegasus, pegasus->phy, MII_BMSR, &tmp)) > >> + if (read_mii_word(pegasus, pegasus->phy, MII_BMSR, &tmp)) > >> return; > >> > >> --- > >> > >> > >> cheers, > >> Petko > >> > >> > >> On Tue, 24 Apr 2007, Dan Williams wrote: > >> > >>> On Tue, 2007-04-24 at 20:48 +0300, [EMAIL PROTECTED] wrote: > >>>>> On Tue, Apr 24, 2007 at 12:49:12PM -0400, Jeff Garzik wrote: > >>>>>> Long term, Greg seemed OK with moving the net drivers from > >>>>>> drivers/usb/net > >>>>>> to drivers/usb/net, in line with the current policy of placing net > >>>>>> drivers > >>>>>> in drivers/net/*, bus agnostic. After that move, sending to netdev > >>>>>> and > >>>>>> me > >>>>>> (as you did here) would be the preferred avenue. > >>>>> > >>>>> Speaking of which, do you want me to do this in the 2.6.22-rc1 > >>>>> timeframe? Usually big code moves like this are good to do right after > >>>>> rc1 comes out as the major churn is usually completed then. > >>>> > >>>> Sorry to interfere, but could you guys wait until tomorrow before > >>>> applying > >>>> the patch to your respective GIT trees? I'd like to check if the code is > >>>> doing the right thing and avoid patch reversal. > >>> > >>> Original problem was that the patch I referenced in the commit message > >>> from Jan 6 2006 switched the return value semantics from > >>> read_mii_word(). Before the patch, read_mii_word returned 1 on success, > >>> 0 on error. After the patch, it returns the generally accepted 0 on > >>> success and !0 on error. > >>> > >>> That causes set_carrier() to return immediately rather than fiddle with > >>> netif_carrier_*. When the Jan 6 2006 patch went in changing the return > >>> values, set_carrier() was not updated for the new return values. > >>> Nothing else in the code cares about read_mii_word()'s return value > >>> except set_carrier(). > >>> > >>> But when the card is brought up and no cable is plugged in, > >>> intr_callback() gets called repeatedly, which itself repeatedly calls > >>> netif_carrier_on() due to the NO_CARRIER check. The comment there about > >>> "NO_CARRIER kicks in on TX failure" seems accurate, because even with no > >>> cable plugged in, and therefore no packets getting transmitted, the > >>> NO_CARRIER check is never true on the Belkin part. Therefore, > >>> netif_carrier_on() is always called as a result of the failure of d[0] & > >>> NO_CARRIER, turning carrier back on even if there is no cable plugged > >>> in. This bulldozes over the MII carrier_check routine too. > >>> > >>> I don't think the intr_callback() code should ever turn the carrier > >>> _on_, because there's that 2*HZ MII carrier check which can certainly > >>> handle the carrier on/off stuff. > >>> > >>> LINK_STATUS appears valid on the Belkin part too, so we can add that as > >>> a reverse-quirk and use LINK_STATUS on parts where it works. If you > >>> think that the NO_CARRIER check should be in _addition_ to the > >>> LINK_STATUS check, that's fine with me, provided that the NO_CARRIER > >>> check only turns carrier off. > >>> > >>> Dan > >>> > >>> > >>> > > > > - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
