From 88ddf0c94bfcc293d033f4cfcc0b438ead968582 Mon Sep 17 00:00:00 2001 From: Arend van Spriel Date: Tue, 3 May 2011 11:35:31 +0200 Subject: [PATCH] staging: brcm80211: provide TSF value in receive status Packets passed to the mac80211 stack have a mactime field in the receive status indicating the actual time it was received by the phy radio. It was not (properly) filled in before this change. Cc: devel@linuxdriverproject.org Cc: linux-wireless@vger.kernel.org Cc: Brett Rudley Cc: Henry Ptasinski Cc: Roland Vossen Signed-off-by: Arend van Spriel Signed-off-by: Greg Kroah-Hartman --- drivers/staging/brcm80211/brcmsmac/wlc_main.c | 50 +++++++++++++++---- 1 file changed, 41 insertions(+), 9 deletions(-) diff --git a/drivers/staging/brcm80211/brcmsmac/wlc_main.c b/drivers/staging/brcm80211/brcmsmac/wlc_main.c index 1f25fc3b6e1f..021384441cb9 100644 --- a/drivers/staging/brcm80211/brcmsmac/wlc_main.c +++ b/drivers/staging/brcm80211/brcmsmac/wlc_main.c @@ -284,6 +284,7 @@ static void wlc_compute_ofdm_plcp(ratespec_t rate, uint length, u8 *plcp); static void wlc_compute_mimo_plcp(ratespec_t rate, uint length, u8 *plcp); static u16 wlc_compute_frame_dur(struct wlc_info *wlc, ratespec_t rate, u8 preamble_type, uint next_frag_len); +static u64 wlc_recover_tsf64(struct wlc_info *wlc, struct wlc_d11rxhdr *rxh); static void wlc_recvctl(struct wlc_info *wlc, d11rxhdr_t *rxh, struct sk_buff *p); static uint wlc_calc_frame_len(struct wlc_info *wlc, ratespec_t rate, @@ -6474,25 +6475,56 @@ void wlc_bcn_li_upd(struct wlc_info *wlc) (wlc->bcn_li_dtim << 8) | wlc->bcn_li_bcn); } +/* + * recover 64bit TSF value from the 16bit TSF value in the rx header + * given the assumption that the TSF passed in header is within 65ms + * of the current tsf. + * + * 6 5 4 4 3 2 1 + * 3.......6.......8.......0.......2.......4.......6.......8......0 + * |<---------- tsf_h ----------->||<--- tsf_l -->||<-RxTSFTime ->| + * + * The RxTSFTime are the lowest 16 bits and provided by the ucode. The + * tsf_l is filled in by wlc_bmac_recv, which is done earlier in the + * receive call sequence after rx interrupt. Only the higher 16 bits + * are used. Finally, the tsf_h is read from the tsf register. + */ +static u64 wlc_recover_tsf64(struct wlc_info *wlc, struct wlc_d11rxhdr *rxh) +{ + u32 tsf_h, tsf_l; + u16 rx_tsf_0_15, rx_tsf_16_31; + + wlc_bmac_read_tsf(wlc->hw, &tsf_l, &tsf_h); + + rx_tsf_16_31 = (u16)(tsf_l >> 16); + rx_tsf_0_15 = rxh->rxhdr.RxTSFTime; + + /* + * a greater tsf time indicates the low 16 bits of + * tsf_l wrapped, so decrement the high 16 bits. + */ + if ((u16)tsf_l < rx_tsf_0_15) { + rx_tsf_16_31 -= 1; + if (rx_tsf_16_31 == 0xffff) + tsf_h -= 1; + } + + return ((u64)tsf_h << 32) | (((u32)rx_tsf_16_31 << 16) + rx_tsf_0_15); +} + static void prep_mac80211_status(struct wlc_info *wlc, d11rxhdr_t *rxh, struct sk_buff *p, struct ieee80211_rx_status *rx_status) { - u32 tsf_l, tsf_h; wlc_d11rxhdr_t *wlc_rxh = (wlc_d11rxhdr_t *) rxh; int preamble; int channel; ratespec_t rspec; unsigned char *plcp; -#if 0 - /* Clearly, this is bogus -- reading the TSF now is wrong */ - wlc_read_tsf(wlc, &tsf_l, &tsf_h); /* mactime */ - rx_status->mactime = tsf_h; - rx_status->mactime <<= 32; - rx_status->mactime |= tsf_l; - rx_status->flag |= RX_FLAG_MACTIME_MPDU; /* clearly wrong */ -#endif + /* fill in TSF and flag its presence */ + rx_status->mactime = wlc_recover_tsf64(wlc, wlc_rxh); + rx_status->flag |= RX_FLAG_MACTIME_MPDU; channel = WLC_CHAN_CHANNEL(rxh->RxChan); -- 2.30.2