From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from xc.sipsolutions.net ([83.246.72.84]:33444 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753184AbZEFQTM (ORCPT ); Wed, 6 May 2009 12:19:12 -0400 Subject: Re: ath5k: scanning while transmitting causes oops on 802.11a capable card From: Johannes Berg To: Pavel Roskin Cc: linux-wireless@vger.kernel.org, ath5k-devel@lists.ath5k.org In-Reply-To: <1241626486.30590.13.camel@mj> References: <1241626486.30590.13.camel@mj> Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-dM+mp1l/5NNyhTMPF3Q6" Date: Wed, 06 May 2009 18:19:07 +0200 Message-Id: <1241626747.4274.0.camel@johannes.local> Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: --=-dM+mp1l/5NNyhTMPF3Q6 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable > If I scan by "iw dev wlan0 scan" while sending data through the > interface, I get a BUG in net/mac80211/tx.c: >=20 > /* RC is busted */ > if (WARN_ON_ONCE(info->control.rates[i].idx >=3D > sband->n_bitrates)) { > info->control.rates[i].idx =3D -1; > continue; > } >=20 > I added this statement inside the condition: >=20 > printk("idx =3D %d, bitrates =3D %d, i =3D %d\n", info->control.rates[i].= idx, > sband->n_bitrates, i); >=20 > The result is: >=20 > idx =3D 9, bitrates =3D 8, i =3D 0 > idx =3D 10, bitrates =3D 8, i =3D 1 > idx =3D 9, bitrates =3D 8, i =3D 2 >=20 > The card is 802.11a capable. My interpretation is that scanning > switches to the 802.11a band temporarily, but doesn't stop transmission. > When transmitting, the rate indices for 2.4 GHz band are checked against > the number of rates in the 5 GHz band, which is indeed 8. There are 12 > rates in the 2.4 GHz band. >=20 > ath5k 0000:0b:00.0: PCI INT A disabled > ath5k 0000:0b:00.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16 > ath5k 0000:0b:00.0: setting latency timer to 64 > ath5k 0000:0b:00.0: registered as 'phy2' > ath: Country alpha2 being used: US > ath: Regpair detected: 0x3a > phy2: Selected rate control algorithm 'minstrel' > ath5k phy2: Atheros AR5414 chip found (MAC: 0xa3, PHY: 0x61) >=20 > I actually had to patch the kernel, or the oops would escalate to a > panic. Perhaps it's a good idea to have that check: I don't think it's just ath5k... I had an oops too. I think some of the pid/minstrel "fixes" broke it but don't know yet. johannes --=-dM+mp1l/5NNyhTMPF3Q6 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- iQIcBAABAgAGBQJKAbhtAAoJEODzc/N7+QmarhYQAKMJK8smy06G09sEThtO2dzO LelfY7ECy8SGqOLAWAaNn15Hzr4981N+77OlIIGmUFKpZjygBvWYjVhhmaOoytvr Uq1q6RQ3boIWMfJrIeB6ccqxTZIIqag72YAG0brVbND25QlSMWc9qx/YEHnowXZw 8DJ8mC9vWVE2HqpTMad+3LwDakn/XXExYGpe14zJfP37QPhVjKIZLpGtcsAK2Kcy +gA7XlB/H2cil7eaUAOdDWiWLr6e/qbfLxiTWHM75mjsLAvowkxd2rYZHi7iHyIv I0YN/+5/pd2PchduYWCL4Sek7aQwbQ6jHOcbnK4Y1AmveUlLIAsWFGLBXGstrQkI ELySdKMQI/6V0uIMTjYMM+KfNy192JrjfqiryaPtF3Kpdk/7NT9/pUR/1xooJwht MEU/xs6xSD8KEecXLlIDH+rFHS9M5wb6t0kOw1Kq81+iaZHstBlBN6rN6dzstUTL RjFIK26XvEhntjmUpsi6Pqxr1oL5Lp9sp4Ra+QyKWArPCbYE7VTwILinWCYtrNfL i5Ra6IPTPs87jVRV5sbFgSxAoFaIcSjWWv8C3ECyHFtoIbHiLwC6y5TReK3hAB9d t2xThiCvqdRkd7RimUEKL3iiuX6ZN/uW6AgRPd1JGDjNxZEAKJLzQuD7FgN0ipMi YGsmfDXK3/ZbsTt7RVU8 =8Qg2 -----END PGP SIGNATURE----- --=-dM+mp1l/5NNyhTMPF3Q6--