On 8/27/20 12:12 PM, Kalle Valo wrote:
Alvin Šipraga <alsi@xxxxxxxxxxxxxxx> writes:
Hi Kalle,
On 7/30/20 2:49 PM, Alvin Šipraga wrote:
This reverts commit 2dc016599cfa9672a147528ca26d70c3654a5423.
Per Atheros documentation to manufacturers, the EEPROM regulatory domain
code 0x0 must always map to "US". In particular, it should not map to a
custom world regulatory domain. For references, see [1] and [2] below.
Furthermore, __ath_regd_init() has a specific condition to set the
country code to "US" in this case, which emits the following log
message:
[ 7.814307] ath: EEPROM indicates default country code should be used
The patch being reverted mistakenly maps 0x0 to the custom world
regulatory domain 0x64 - the most restrictive of the world regulatory
domains. The premise of the patch is that in the case of EEPROM
regulatory domain code 0x0, ath_is_world_regd() should return true. But,
as stated above, 0x0 should not map to a world regulatory domain, and so
the function should return false. The original behaviour, whereby
NL80211_REGDOM_SET_BY_COUNTRY_IE is ignored, was correct according to
the manufacturer's intent and should not have been changed.
[1] https://wireless.wiki.kernel.org/en/users/drivers/ath#the_0x0_regulatory_domain
[2] http://article.gmane.org/gmane.linux.kernel.wireless.general/38410
Fixes: 2dc016599cfa ("ath: add support for special 0x0 regulatory domain")
Cc: Wen Gong <wgong@xxxxxxxxxxxxxx>
Cc: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
Cc: linux-wireless@xxxxxxxxxxxxxxx
Tested-on: QCA9880 hw2.0 PCI 10.2.4-1.0-00047
Signed-off-by: Alvin Šipraga <alsi@xxxxxxxxxxxxxxx>
---
drivers/net/wireless/ath/regd.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
Do you have any feedback on this patch? No problem if you simply have
not looked yet - I am not sure what kind of lead time to expect on the
list. But without the patch, a (correctly) programmed 0x0 (US) card
will not be able to operate on 5GHz channels without some hacking. I
have cited some references to justify reverting this patch, so I would
like to know if anything further should be done to get this into
future kernels?
I wonder also if Wen Gong could comment, whose patch I am reverting in
the first place. Maybe there is something I am missing?
I'm working on it, I just need to check something internally first.
BTW, Brian submitted an identical revert first so I'm planning to use
his patch instead of yours:
https://patchwork.kernel.org/patch/11573585/
Hi Kalle,
Thank you for the update, glad to hear it. Sorry that I did not notice
Brian's patch - I guess you can close my one on patchwork then.
Kind regards,
Alvin
