On 31 May 2016 at 17:58, Rafał Miłecki <zajec5@xxxxxxxxx> wrote: > On 31 May 2016 at 15:14, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: >> On Tue, 2016-05-31 at 15:10 +0200, Rafał Miłecki wrote: >> >>> > Unfortunately, I get compiler warnings about width_* being possibly >>> > used uninitialized. Can you address that please? >>> It's nice your compiled got this mistake, my didn't. There were >>> actually meant to be static. I'll fix that. >> >> I actually think the compiler is wrong, and there's no reason for them >> to be static, is there? >> >> The first iteration of the loop should always initialize since -1 is >> used for initialization? >> >> In any case, I'd prefer to avoid static, if necessary pass some kind of >> context structure in to the function? > > I don't know if we can assume getting all three attributes: > NL80211_BAND_ATTR_HT_CAPA > NL80211_BAND_ATTR_VHT_CAPA > NL80211_BAND_ATTR_FREQS > at the same single handler call. I guess not. That's why I believe we > need all width_* to be static, so they keep value across separated > handler calls. Yes, this is definitely the case. I did some debugging from user space and printed one line per a single handler call: [i:0] WIPHY_BANDS:0 [i:1] WIPHY_BANDS:0 [i:2] WIPHY_BANDS:0 [i:3] WIPHY_BANDS:1 ATTR_HT_CAPA:1 ATTR_VHT_CAPA:0 ATTR_FREQS:0 [i:4] WIPHY_BANDS:1 ATTR_HT_CAPA:1 ATTR_VHT_CAPA:1 ATTR_FREQS:0 [i:5] WIPHY_BANDS:1 ATTR_HT_CAPA:0 ATTR_VHT_CAPA:0 ATTR_FREQS:1 [i:6] WIPHY_BANDS:1 ATTR_HT_CAPA:0 ATTR_VHT_CAPA:0 ATTR_FREQS:1 [i:7] WIPHY_BANDS:1 ATTR_HT_CAPA:0 ATTR_VHT_CAPA:0 ATTR_FREQS:1 [i:8] WIPHY_BANDS:1 ATTR_HT_CAPA:0 ATTR_VHT_CAPA:0 ATTR_FREQS:1 [i:9] WIPHY_BANDS:1 ATTR_HT_CAPA:0 ATTR_VHT_CAPA:0 ATTR_FREQS:1 [i:10] WIPHY_BANDS:1 ATTR_HT_CAPA:0 ATTR_VHT_CAPA:0 ATTR_FREQS:1 [i:11] WIPHY_BANDS:1 ATTR_HT_CAPA:0 ATTR_VHT_CAPA:0 ATTR_FREQS:1 [i:12] WIPHY_BANDS:1 ATTR_HT_CAPA:0 ATTR_VHT_CAPA:0 ATTR_FREQS:1 [i:13] WIPHY_BANDS:1 ATTR_HT_CAPA:0 ATTR_VHT_CAPA:0 ATTR_FREQS:1 (...) As you can see we have ATTR_HT_CAPA and ATTR_VHT_CAPA set only in few early calls. It means we need to extract info from them and store it in static variables. -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
