Date: Tue, 30 May 2023 23:40:43 +0000 (UTC) From: "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net> To: John Nielsen <lists@jnielsen.net> Cc: "wireless@freebsd.org" <wireless@FreeBSD.org> Subject: Re: Help me grok the ath(4) device attach code Message-ID: <q921p430-oq56-qo4n-rq49-0o7008pr40n3@yvfgf.mnoonqbm.arg> In-Reply-To: <49AEA1CB-FA85-432F-89D7-8C49B5F3A344@jnielsen.net> References: <49AEA1CB-FA85-432F-89D7-8C49B5F3A344@jnielsen.net>
next in thread | previous in thread | raw e-mail | index | archive | help
This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --1098556516-1091208796-1685490045=:48381 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8BIT On Tue, 30 May 2023, John Nielsen wrote: > I’m trying to wrap my head around the code in sys/dev/ath/ath_hal , partly for my own edification but mostly due to wanting to fix this bug: > https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=255337 > > The card in question is an AR9462, branded (I think) as a Dell Wireless 1901 with this ID: > vendor=0x168c device=0x0034 subvendor=0x1028 subdevice=0x020d > > The card is identified and appears to initialize correctly but it has a default/bogus MAC address of 00:02:03:04:05:06 and is never able to scan any networks. It does work fine under Linux, so I’m attempting to compare the two codebases. But since I’m not a device developer and haven’t done much C since my undergraduate work, I’m having a bit of trouble. > > I’m open to any pointers but I’d specifically like to work out the following (unless I’m way off base, in which case I’d like to know that too): > > 1) Where does the default MAC address come from? In the Linux driver it looks like it’s here: > https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/tree/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c#n49 > I don’t see any such definition in the FreeBSD code. No idea, but you should end up in a call to ar9300_get_mac_address() from sys/contrib/dev/ath/ath_hal/ar9300/ar9300_misc.c if my guess is right. The call comes from sys/dev/ath/if_ath.c ath_hal_getmac(). Hope that helps you to trace this. > 2) When ath_hal_attach() calls chip->attach(), which code is actually called (and how/where is that determined)? > > 3) Is there any equivalent in the FreeBSD code for this Linux process of trying to read the EEPROM from multiple different addresses? (Is it necessary?) > https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/tree/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c#n3299 > See also: > https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/commit/drivers/net/wireless/ath/ath9k?id=528782ecf59f7bab2f1368628a479f49be59b512 > and the definitions here: > https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/tree/drivers/net/wireless/ath/ath9k/ar9003_eeprom.h#n78 > > (I don’t see any of those BASE_ADDR values referenced or defined anywhere in FreeBSD) > > 4) In general, what code should I be looking at to see how the EEPROM is read and interpreted for a specific card? > > Any help appreciated! > > Thanks, > > JN > > > -- Bjoern A. Zeeb r15:7 --1098556516-1091208796-1685490045=:48381--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?q921p430-oq56-qo4n-rq49-0o7008pr40n3>