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Date:      Thu, 1 Jun 2023 23:28:07 -0600
From:      John Nielsen <lists@jnielsen.net>
To:        Adrian Chadd <adrian@freebsd.org>
Cc:        "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net>, "wireless@freebsd.org" <wireless@freebsd.org>
Subject:   Re: Help me grok the ath(4) device attach code
Message-ID:  <8CEDC118-5FCA-434D-B7F7-B0C4A7AC3ACC@jnielsen.net>
In-Reply-To: <5264D290-EB82-4D24-A812-85E3E6B5C88E@jnielsen.net>
References:  <49AEA1CB-FA85-432F-89D7-8C49B5F3A344@jnielsen.net> <q921p430-oq56-qo4n-rq49-0o7008pr40n3@yvfgf.mnoonqbm.arg> <E6DF8709-2767-48D3-AED1-D0608F5AABCF@jnielsen.net> <CAJ-VmokUORGzQz6bOhutucy1xTv_1ZwP0vOZN=6vW1wusCLJpg@mail.gmail.com> <85BF3AB2-2EBF-4398-A507-ABA35505A56C@jnielsen.net> <CAJ-VmokL_Kdrgtv3YT6U=yKhr4d-wkba3Vx3AssfY3-iMuBT5Q@mail.gmail.com> <BACFD661-E94B-4F50-93EE-91450EBD2212@jnielsen.net> <CAJ-VmonEoAGTN6XcDZQeU6Z=pcZiD-qNhPMYm%2BEXhiVbotwYcw@mail.gmail.com> <5264D290-EB82-4D24-A812-85E3E6B5C88E@jnielsen.net>

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> On May 31, 2023, at 1:52 PM, John Nielsen <lists@jnielsen.net> wrote:
>=20
>> On May 30, 2023, at 11:17 PM, Adrian Chadd <adrian@freebsd.org> =
wrote:
>>=20
>> On Tue, 30 May 2023 at 22:12, John Nielsen <lists@jnielsen.net =
<mailto:lists@jnielsen.net>> wrote:
>>>> On May 30, 2023, at 10:56 PM, Adrian Chadd <adrian@freebsd.org =
<mailto:adrian@freebsd.org>> wrote:
>>>>=20
>>>> On Tue, 30 May 2023 at 20:56, John Nielsen <lists@jnielsen.net =
<mailto:lists@jnielsen.net>> wrote:
>>>>> > On May 30, 2023, at 8:02 PM, Adrian Chadd <adrian@freebsd.org =
<mailto:adrian@freebsd.org>> wrote:
>>>>> >=20
>>>>> > Err, if it's coming up w/ that MAC then it's not finding and =
attaching right to the OTP/EEPROM calibration information. That's the =
big red flag that it in general won't work correctly.
>>>>> >=20
>>>>> > Can you provide the rest of the ath_hal messages? I'd like to =
see what it's saying during boot around it checking the EEPROM/OTP =
contents. It's possible there's some work around required for this NIC.
>>>>>=20
>>>>> He speaks! Thanks for taking the time. I just realized that =
ath_hal_printf doesn=E2=80=99t prepend =E2=80=9Cath%d=E2=80=9D so I=E2=80=99=
ve been missing those messages when grep-ing. Here=E2=80=99s the whole =
snippet:
>>>>>=20
>>>>> ath0: <Atheros AR946x/AR948x> mem 0xf7a00000-0xf7a7ffff at device =
0.0 on pci4
>>>>> ar9300_flash_map: unimplemented for now
>>>>> Restoring Cal data from DRAM
>>>>> Restoring Cal data from EEPROM
>>>>> Restoring Cal data from Flash
>>>>> Restoring Cal data from Flash
>>>>> Restoring Cal data from OTP
>>>>> ar9300_eeprom_restore_internal[4338] No vaid CAL, calling default =
template
>>>>> ar9300_hw_attach: ar9300_eeprom_attach returned 0
>>>>=20
>>>> Yeah, this bit right here is the problem. It's not finding a valid =
calibration.
>>>=20
>>>> oh err, is there a wifi enable/disable switch or something? maybe =
it's asserted and somehow it's mucking up the NIC?
>>>=20
>>> There is a physical switch and it=E2=80=99s in the =E2=80=9Cenable=E2=80=
=9D position.
>>>=20
>>>>  I wonder what ath9k is doing here? Is there some weird pci based =
workaround/flag for the given NIC PCI id?
>>>=20
>>> That was the first breadcrumb BZ threw me but I can=E2=80=99t find =
anything. There are some .driver_data hints for adjacent subdevice IDs =
but none for this one (Dell 0x020d) in either FreeBSD or Linux that I =
could find.
>>>=20
>>> [snip]
>>> There is this commit in ath9k which mentions an alternative EEPROM =
address, but I=E2=80=99m not sure if that=E2=80=99s relevant. =46rom =
what I can tell the probe should succeed at the normal base_address =
0x3ff instead of needing to try the =E2=80=9C4k=E2=80=9D one 0xfff.
>>> =
https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/commit/drive=
rs/net/wireless/ath/ath9k?id=3D528782ecf59f7bab2f1368628a479f49be59b512
>>=20
>> Yeah i'd try that. It'd be nice if I knew that the NIC used OTP or =
EEPROM though.
>>=20
>> There's known issues with all the Atheros chips (sigh) with how the =
EEPROM and PCIe bus reset .. interact.
>> (If the bus reset is too short then the EEPROM state machine gets =
stuck and nothing gets read.) It makes debugging this hard because the =
NIC itself will work in another device fine, because it's the BIOS/ACPI =
code. :(
>=20
> The 4k EEPROM read didn=E2=80=99t work. But I did notice that where it =
says it=E2=80=99s restoring Cal data from OTP it actually just does an =
EEPROM read again. Shouldn=E2=80=99t this line be a call to =
ar9300_otp_read() instead of ar9300_eeprom_restore_internal_address()?
>=20
> =
https://cgit.freebsd.org/src/tree/sys/contrib/dev/ath/ath_hal/ar9300/ar930=
0_eeprom.c#n4292
>=20
> Otherwise it doesn=E2=80=99t use the 0x14000 (0x30000 for some cards) =
OTP offset as a starting point.

I=E2=80=99d love to know if I=E2=80=99m up in the night about my theory =
above about the OTP call not actually happening. In the meantime I=E2=80=99=
ll carry on either trying to find/build a Linux kernel with =
CONFIG_ATH_DEBUG enabled that I can boot on the laptop (to see which =
EEPROM retrieval/check actually succeeds) and/or try to reimplement bits =
from the ath9k ar9300_eeprom_restore_internal() to match its behavior on =
FreeBSD.
( =
https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/tree/drivers=
/net/wireless/ath/ath9k/ar9003_eeprom.c#n3266 )

Thanks,

JN


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<html><head><meta http-equiv=3D"content-type" content=3D"text/html; =
charset=3Dutf-8"></head><body style=3D"overflow-wrap: break-word; =
-webkit-nbsp-mode: space; line-break: =
after-white-space;"><div><blockquote type=3D"cite"><div>On May 31, 2023, =
at 1:52 PM, John Nielsen &lt;lists@jnielsen.net&gt; wrote:</div><br =
class=3D"Apple-interchange-newline"><div><meta charset=3D"UTF-8"><div =
style=3D"caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: =
12px; font-style: normal; font-variant-caps: normal; font-weight: 400; =
letter-spacing: normal; text-align: start; text-indent: 0px; =
text-transform: none; white-space: normal; word-spacing: 0px; =
-webkit-text-stroke-width: 0px; text-decoration: none;"><blockquote =
type=3D"cite"><div>On May 30, 2023, at 11:17 PM, Adrian Chadd =
&lt;adrian@freebsd.org&gt; wrote:</div><div><div dir=3D"ltr"><br><div =
class=3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Tue, 30 =
May 2023 at 22:12, John Nielsen &lt;<a =
href=3D"mailto:lists@jnielsen.net">lists@jnielsen.net</a>&gt; =
wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"margin: 0px =
0px 0px 0.8ex; border-left-width: 1px; border-left-style: solid; =
border-left-color: rgb(204, 204, 204); padding-left: =
1ex;"><div><div><blockquote type=3D"cite"><div>On May 30, 2023, at 10:56 =
PM, Adrian Chadd &lt;<a href=3D"mailto:adrian@freebsd.org" =
target=3D"_blank">adrian@freebsd.org</a>&gt; wrote:</div><div><br =
style=3D"font-family: Helvetica; font-size: 12px; font-style: normal; =
font-variant-caps: normal; font-weight: 400; letter-spacing: normal; =
text-align: start; text-indent: 0px; text-transform: none; white-space: =
normal; word-spacing: 0px; text-decoration: none;"><div =
class=3D"gmail_quote" style=3D"font-family: Helvetica; font-size: 12px; =
font-style: normal; font-variant-caps: normal; font-weight: 400; =
letter-spacing: normal; text-align: start; text-indent: 0px; =
text-transform: none; white-space: normal; word-spacing: 0px; =
text-decoration: none;"><div dir=3D"ltr" class=3D"gmail_attr">On Tue, 30 =
May 2023 at 20:56, John Nielsen &lt;<a href=3D"mailto:lists@jnielsen.net" =
target=3D"_blank">lists@jnielsen.net</a>&gt; wrote:<br></div><blockquote =
class=3D"gmail_quote" style=3D"margin: 0px 0px 0px 0.8ex; =
border-left-width: 1px; border-left-style: solid; border-left-color: =
rgb(204, 204, 204); padding-left: 1ex;">&gt; On May 30, 2023, at 8:02 =
PM, Adrian Chadd &lt;<a href=3D"mailto:adrian@freebsd.org" =
target=3D"_blank">adrian@freebsd.org</a>&gt; =
wrote:<br>&gt;<span>&nbsp;</span><br>&gt; Err, if it's coming up w/ that =
MAC then it's not finding and attaching right to the OTP/EEPROM =
calibration information. That's the big red flag that it in general =
won't work correctly.<br>&gt;<span>&nbsp;</span><br>&gt; Can you provide =
the rest of the ath_hal messages? I'd like to see what it's saying =
during boot around it checking the EEPROM/OTP contents. It's possible =
there's some work around required for this NIC.<br><br>He speaks! Thanks =
for taking the time. I just realized that ath_hal_printf doesn=E2=80=99t =
prepend =E2=80=9Cath%d=E2=80=9D so I=E2=80=99ve been missing those =
messages when grep-ing. Here=E2=80=99s the whole snippet:<br><br>ath0: =
&lt;Atheros AR946x/AR948x&gt; mem 0xf7a00000-0xf7a7ffff at device 0.0 on =
pci4<br>ar9300_flash_map: unimplemented for now<br>Restoring Cal data =
from DRAM<br>Restoring Cal data from EEPROM<br>Restoring Cal data from =
Flash<br>Restoring Cal data from Flash<br>Restoring Cal data from =
OTP<br>ar9300_eeprom_restore_internal[4338] No vaid CAL, calling default =
template<br>ar9300_hw_attach: ar9300_eeprom_attach returned =
0<br></blockquote><div><br></div><div>Yeah, this bit right here is the =
problem. It's not finding a valid =
calibration.</div></div></div></blockquote><div><br></div><div><blockquote=
 type=3D"cite"><div>oh err, is there a wifi enable/disable switch or =
something? maybe it's asserted and somehow it's mucking up the =
NIC?</div></blockquote><br></div><div>There is a physical switch and =
it=E2=80=99s in the =E2=80=9Cenable=E2=80=9D =
position.</div><br><blockquote type=3D"cite"><div><div =
class=3D"gmail_quote" style=3D"font-family: Helvetica; font-size: 12px; =
font-style: normal; font-variant-caps: normal; font-weight: 400; =
letter-spacing: normal; text-align: start; text-indent: 0px; =
text-transform: none; white-space: normal; word-spacing: 0px; =
text-decoration: none;"><div>&nbsp;I wonder what ath9k is doing here? Is =
there some weird pci based workaround/flag for the given NIC PCI =
id?</div></div></div></blockquote><br></div><div>That was the first =
breadcrumb BZ threw me but I can=E2=80=99t find anything. There are some =
.driver_data hints for adjacent subdevice IDs but none for this one =
(Dell 0x020d) in either FreeBSD or Linux that I could =
find.</div><div><br></div><div>[snip]</div>There is this commit in ath9k =
which mentions an alternative EEPROM address, but I=E2=80=99m not sure =
if that=E2=80=99s relevant. =46rom what I can tell the probe should =
succeed at the normal base_address 0x3ff instead of needing to try the =
=E2=80=9C4k=E2=80=9D one 0xfff.<br><div><a =
href=3D"https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/comm=
it/drivers/net/wireless/ath/ath9k?id=3D528782ecf59f7bab2f1368628a479f49be5=
9b512" =
target=3D"_blank">https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/at=
h.git/commit/drivers/net/wireless/ath/ath9k?id=3D528782ecf59f7bab2f1368628=
a479f49be59b512</a></div></div></blockquote><div><br></div><div>Yeah i'd =
try that. It'd be nice if I knew that the NIC used OTP or EEPROM =
though.</div><div><br></div><div>There's known issues with all the =
Atheros chips (sigh) with how the EEPROM and PCIe bus reset .. =
interact.</div><div>(If the bus reset is too short then the EEPROM state =
machine gets stuck and nothing gets read.) It makes debugging this hard =
because the NIC itself will work in another device fine, because it's =
the BIOS/ACPI code. :(</div></div></div></div></blockquote></div><br =
style=3D"caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: =
12px; font-style: normal; font-variant-caps: normal; font-weight: 400; =
letter-spacing: normal; text-align: start; text-indent: 0px; =
text-transform: none; white-space: normal; word-spacing: 0px; =
-webkit-text-stroke-width: 0px; text-decoration: none;"><div =
style=3D"caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: =
12px; font-style: normal; font-variant-caps: normal; font-weight: 400; =
letter-spacing: normal; text-align: start; text-indent: 0px; =
text-transform: none; white-space: normal; word-spacing: 0px; =
-webkit-text-stroke-width: 0px; text-decoration: none;">The 4k EEPROM =
read didn=E2=80=99t work. But I did notice that where it says it=E2=80=99s=
 restoring Cal data from OTP it actually just does an EEPROM read again. =
Shouldn=E2=80=99t this line be a call to ar9300_otp_read() instead of =
ar9300_eeprom_restore_internal_address()?</div><div style=3D"caret-color: =
rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: =
normal; font-variant-caps: normal; font-weight: 400; letter-spacing: =
normal; text-align: start; text-indent: 0px; text-transform: none; =
white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; =
text-decoration: none;"><br></div><div style=3D"caret-color: rgb(0, 0, =
0); font-family: Helvetica; font-size: 12px; font-style: normal; =
font-variant-caps: normal; font-weight: 400; letter-spacing: normal; =
text-align: start; text-indent: 0px; text-transform: none; white-space: =
normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; =
text-decoration: none;"><a =
href=3D"https://cgit.freebsd.org/src/tree/sys/contrib/dev/ath/ath_hal/ar93=
00/ar9300_eeprom.c#n4292">https://cgit.freebsd.org/src/tree/sys/contrib/de=
v/ath/ath_hal/ar9300/ar9300_eeprom.c#n4292</a></div><div =
style=3D"caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: =
12px; font-style: normal; font-variant-caps: normal; font-weight: 400; =
letter-spacing: normal; text-align: start; text-indent: 0px; =
text-transform: none; white-space: normal; word-spacing: 0px; =
-webkit-text-stroke-width: 0px; text-decoration: none;"><br></div><div =
style=3D"caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: =
12px; font-style: normal; font-variant-caps: normal; font-weight: 400; =
letter-spacing: normal; text-align: start; text-indent: 0px; =
text-transform: none; white-space: normal; word-spacing: 0px; =
-webkit-text-stroke-width: 0px; text-decoration: none;">Otherwise it =
doesn=E2=80=99t use the 0x14000 (0x30000 for some cards) OTP offset as a =
starting point.</div></div></blockquote></div><br><div>I=E2=80=99d love =
to know if I=E2=80=99m up in the night about my theory above about the =
OTP call not actually happening. In the meantime I=E2=80=99ll carry on =
either trying to find/build a Linux kernel with CONFIG_ATH_DEBUG enabled =
that I can boot on the laptop (to see which EEPROM retrieval/check =
actually succeeds) and/or try to reimplement bits from the ath9k =
ar9300_eeprom_restore_internal() to match its behavior on =
FreeBSD.</div><div>( =
https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git/tree/drivers=
/net/wireless/ath/ath9k/ar9003_eeprom.c#n3266 =
)</div><div><br></div><div>Thanks,</div><div><br></div><div>JN</div><div><=
br></div></body></html>=

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