2015-06-18 17:34 GMT+02:00 Nick Kossifidis <mickflemm@xxxxxxxxx>: > 2015-06-18 16:13 GMT+02:00 Nick Kossifidis <mickflemm@xxxxxxxxx>: >> 2015-06-18 12:36 GMT+02:00 Zefir Kurtisi <zefir.kurtisi@xxxxxxxxxxx>: >>> On 06/18/2015 10:43 AM, Nick Kossifidis wrote: >>>> max_index is a 6bit signed integer in both cases (sorry for the 5bit >>>> typo in the comments), so the current function handles it correctly >>>> for both HT20 and dynamic HT20/40 modes (I've tested it extensively). >>>> Also you don't handle the negative indices we get from the hardware >>>> (you just remove the sign). Have you tested this and if you did on >>>> which hardware did you do the test ? >>>> >>>> 2015-06-16 11:21 GMT+02:00 Zefir Kurtisi <zefir.kurtisi@xxxxxxxxxxx>: >>>>> [...] >>>>> +/* return the max magnitude from the all/upper/lower bins >>>>> + * >>>>> + * in HT20: 6-bit signed number of range -28 to +27 >>>>> + * in HT40: 6-bit unsigned number of range 0 to +63 >>>>> + * (upper sub-channel index 0 is DC) >>>>> + * >>>>> + * Correct interpretation of the value has to be done at caller >>>>> + */ >>> >>> The comment above is taken from developer NDA documents and should be correct. >>> With that, in HT40 mode the max_index value has to be taken as is, while in HT20 >>> it needs to be shifted to the unsigned range. >>> >> >> I have NDA documents as well stating that the indices are from -64 to >> 63 (-64 to -1, 1 to 63 and 0 is DC), you can check out for yourself >> that we get 128bins on dynamic HT20/40, see the header files too: >> >> #define SPECTRAL_HT20_40_NUM_BINS 128 >> >> and/or the received packet length. Maybe you are talking about >> "static" HT40 (I don't see anything about that on the documents I >> have) or something else. >> > > To clarify this a bit: It's 0 - 63 for lower bins and 0 - 64 (not 63) > for upper bins and since we want an array index of 0 - 128 we add the > index of 0 to the upper max_idx (on the caller). You are right that > the current comment there is wrong (it even mentions 5bit ints) so > feel free to fix that but the code works as expected and it's much > more readable than doing "^ 0x20 - 4" on the caller (plus it handles > both signed and unsigned cases so no problem there). > Arghh, I need to sleep asap :P 0 - 64 for lower bins and 0 - 63 for upper bins... -- GPG ID: 0xEE878588 As you read this post global entropy rises. Have Fun ;-) Nick -- 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
