Re: [PATCH] brcmfmac: use ISO3166 country code and 0 rev as fallback on some devices

[Soeren Moch <smoch@web.de>]

On 18.12.21 19:56, Hans de Goede wrote:
> This is a second attempt at honering the country code send out by access
> points. This was first added in commit b0b524f079a2 ("brcmfmac: use
> ISO3166 country code and 0 rev as fallback").
>
> Subsequently this was reverted in commit 151a7c12c4fc ("Revert "brcmfmac:
> use ISO3166 country code and 0 rev as fallback""), because it was causing
> issues with AP mode on some brcmfmac models (specifically on BCM4359/9).
>
> Many devices ship with a nvram ccode value of X2/XT/XU/XV/ALL which are
> all special world-wide compatibility ccode-s. Most of these world-wide
> ccode-s allow passive scan mode only for 2.4GHz channels 12-14,
> only enabling them when an AP is seen on them.
>
> But at least on brcmfmac43455 devices this is not working correctly, these
> do not see accesspoints on channels 12-14 unless the ccode is changes to
> a country where these channels are allowed.
>
> Translating received country codes to an ISO3166 country code and 0 rev
> ccreq fixes devices using a brcmfmac43455 with a X2/XT/XU/XV/ALL ccode
> not seeing accesspoints on channels 12-14.
>
> To avoid this causing issues on other brcmfmac models again, the
> fallback is limited to only brcmfmac4345* chips this time.
>
> Cc: Shawn Guo <shawn.guo@linaro.org>
> Cc: Soeren Moch <smoch@web.de>
> Cc: Fabio Aiuto <fabioaiuto83@gmail.com>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Unsurprisingly this does not hurt on BCM4359/9. So FWIW

Tested-by: Soeren Moch <smoch@web.de>  # on BCM4359/9
> ---
>  .../broadcom/brcm80211/brcmfmac/cfg80211.c    | 33 +++++++++++++++----
>  1 file changed, 27 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> index fb727778312c..c10ac839dd26 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> @@ -16,6 +16,7 @@
>  #include <brcmu_utils.h>
>  #include <defs.h>
>  #include <brcmu_wifi.h>
> +#include <brcm_hw_ids.h>
>  #include "core.h"
>  #include "debug.h"
>  #include "tracepoint.h"
> @@ -7455,6 +7456,16 @@ int brcmf_cfg80211_wait_vif_event(struct brcmf_cfg80211_info *cfg,
>  				  vif_event_equals(event, action), timeout);
>  }
>
> +static bool brmcf_use_iso3166_ccode_fallback(struct brcmf_pub *drvr)
> +{
> +	switch (drvr->bus_if->chip) {
> +	case BRCM_CC_4345_CHIP_ID:
> +		return true;
> +	default:
> +		return false;
> +	}
> +}
> +
>  static s32 brcmf_translate_country_code(struct brcmf_pub *drvr, char alpha2[2],
>  					struct brcmf_fil_country_le *ccreq)
>  {
> @@ -7463,18 +7474,28 @@ static s32 brcmf_translate_country_code(struct brcmf_pub *drvr, char alpha2[2],
>  	s32 found_index;
>  	int i;
>
> -	country_codes = drvr->settings->country_codes;
> -	if (!country_codes) {
> -		brcmf_dbg(TRACE, "No country codes configured for device\n");
> -		return -EINVAL;
> -	}
> -
>  	if ((alpha2[0] == ccreq->country_abbrev[0]) &&
>  	    (alpha2[1] == ccreq->country_abbrev[1])) {
>  		brcmf_dbg(TRACE, "Country code already set\n");
>  		return -EAGAIN;
>  	}
>
> +	country_codes = drvr->settings->country_codes;
> +	if (!country_codes) {
> +		if (brmcf_use_iso3166_ccode_fallback(drvr)) {
> +			brcmf_dbg(TRACE, "No country codes configured for device, using ISO3166 code and 0 rev\n");
> +			memset(ccreq, 0, sizeof(*ccreq));
> +			ccreq->country_abbrev[0] = alpha2[0];
> +			ccreq->country_abbrev[1] = alpha2[1];
> +			ccreq->ccode[0] = alpha2[0];
> +			ccreq->ccode[1] = alpha2[1];
> +			return 0;
> +		}
> +
> +		brcmf_dbg(TRACE, "No country codes configured for device\n");
> +		return -EINVAL;
> +	}
> +
>  	found_index = -1;
>  	for (i = 0; i < country_codes->table_size; i++) {
>  		cc = &country_codes->table[i];