From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1i8PMK-0000Qa-7P for ath10k@lists.infradead.org; Thu, 12 Sep 2019 13:42:05 +0000 From: Kalle Valo Subject: Re: [PATCH] ath10k: Fix channel info parsing for non tlv target References: <1552044366-9186-1-git-send-email-pillair@codeaurora.org> Date: Thu, 12 Sep 2019 16:41:58 +0300 In-Reply-To: <1552044366-9186-1-git-send-email-pillair@codeaurora.org> (Rakesh Pillai's message of "Fri, 8 Mar 2019 16:56:06 +0530") Message-ID: <87r24lk4wp.fsf@kamboji.qca.qualcomm.com> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "ath10k" Errors-To: ath10k-bounces+kvalo=adurom.com@lists.infradead.org To: Rakesh Pillai Cc: linux-wireless@vger.kernel.org, ath10k@lists.infradead.org Rakesh Pillai writes: > The tlv targets such as WCN3990 send more data in > the chan info event, which is not sent by the non tlv > targets. There is a minimum size check in the wmi event for > non-tlv targets and hence we cannot update the common > channel info structure. > > If the common channel info structure is updated, the > size check for chan info event for non-tlv targets > will fail and return -EPROTO This is the code in question: static int ath10k_wmi_op_pull_ch_info_ev(struct ath10k *ar, struct sk_buff *skb, struct wmi_ch_info_ev_arg *arg) { struct wmi_chan_info_event *ev = (void *)skb->data; if (skb->len < sizeof(*ev)) return -EPROTO; skb_pull(skb, sizeof(*ev)); arg->err_code = ev->err_code; arg->freq = ev->freq; arg->cmd_flags = ev->cmd_flags; arg->noise_floor = ev->noise_floor; arg->rx_clear_count = ev->rx_clear_count; arg->cycle_count = ev->cycle_count; return 0; } And here I see a disconnection between firmware and ath10k. The design philosophy in firmware is that if the firmware does not provide all fields, for example cycle_count in this event, the host driver is supposed to replace the missing field with value zero and continue normally. Obviously ath10k does not do that and instead it drops the whole WMI event, which causes breakup like this. The quick fix (having separate structs for TLV and 10.x interfaces) in this patch is ok, but in the future if similar field additions arise we need to remember to fix ath10k event parsing so that both new ath10k will continue to work with older firmwares. -- https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k