From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ryder Lee Subject: Re: [PATCH] mt76: mt7615: add support for per-chain signal strength reporting Date: Mon, 10 Jun 2019 15:12:09 +0800 Message-ID: <1560150729.14203.11.camel@mtkswgap22> References: <3912a2863e858f3623ced61737836e42c7b19149.1560071167.git.ryder.lee@mediatek.com> <1560132590.28258.5.camel@mtkswgap22> <1560140541.5606.12.camel@mtkswgap22> <64662021-8e5a-91b5-9afb-3c9005564d19@newmedia-net.de> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <64662021-8e5a-91b5-9afb-3c9005564d19@newmedia-net.de> Sender: linux-kernel-owner@vger.kernel.org To: Sebastian Gottschall Cc: Sean Wang , Chih-Min Chen , YF Luo , linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, Yiwei Chung , linux-mediatek@lists.infradead.org, Roy Luo , Lorenzo Bianconi , Felix Fietkau List-Id: linux-mediatek@lists.infradead.org On Mon, 2019-06-10 at 06:47 +0200, Sebastian Gottschall wrote: > okay. curious is, that my variant works with sane results too. > i will test your variant and check the results > > Sebastian Please don't top post as it's hard to track the thread. More specifically, IBRSSI is obtained from packet's L-STF portion and MTK HW PD (packet detection) will take it as a reference. (with variation more or less) As for RCPI which is calculated from packet's data portion. The other MTK chipsets may use IBRSSI as their baseband couldn't report RCPI. Ryder > Am 10.06.2019 um 06:22 schrieb Ryder Lee: > > On Mon, 2019-06-10 at 10:09 +0800, Ryder Lee wrote: > >> On Sun, 2019-06-09 at 16:44 +0200, Sebastian Gottschall wrote: > >>> according to my findings > >>> > >>> MT_RXV4_RCPI1 is part of rx descriptor 4 and not 3 > >>> so it must be rxdg4 = rxd[4] etc. > >> RXV start from 1 in the code. > >> > >> That is: RXV1 <-> rxdg0, RXV2 <-> rxdg1 ...so RXV4 <-> rxdg3 > >> > >>> however rxdg3 contains MT_RXV3_IB_RSSIRX which can be used for signal calculation. > >>> i already wrote a similar code for this driver which i sended to felix a long time ago. > >>> my variant looks like > >>> status->signal = (FIELD_GET(MT_RXV3_IB_RSSIRX, rxdg3) - 220) / 2; > >>> status->chain_signal[0] = (FIELD_GET(MT_RXV4_RCPI0, rxdg4) - 220) / 2; > >>> status->chain_signal[1] = (FIELD_GET(MT_RXV4_RCPI1, rxdg4) - 220) / 2; > >>> status->chain_signal[2] = (FIELD_GET(MT_RXV4_RCPI2, rxdg4) - 220) / 2; > >>> status->chain_signal[3] = (FIELD_GET(MT_RXV4_RCPI3, rxdg4) - 220) / 2; > > mt7615 actually doesn't use in-band RSSI for signal calculation, but it > > occurs to me that i should modify the code to compare per-chain's > > signal. Something like this: > > > > status->chain_signal[0] = to_rssi(MT_RXV4_RCPI0, rxdg3); > > status->chain_signal[1] = to_rssi(MT_RXV4_RCPI1, rxdg3); > > status->chain_signal[2] = to_rssi(MT_RXV4_RCPI2, rxdg3); > > status->chain_signal[3] = to_rssi(MT_RXV4_RCPI3, rxdg3); > > status->signal = status->chain_signal[0]; > > > > switch (status->chains) { > > case 0xf: > > status->signal = max(status->signal, > > status->chain_signal[3]); > > case 0x7: > > status->signal = max(status->signal, > > status->chain_signal[2]); > > case 0x3: > > status->signal = max(status->signal, > > status->chain_signal[1]); > > break; > > default: > > break; > > } > > > > > > I could send a v2 or you can take care of that. > > > > Ryder > > > >