Return-path: Received: from mail-oi0-f65.google.com ([209.85.218.65]:37476 "EHLO mail-oi0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751959AbdI0NPu (ORCPT ); Wed, 27 Sep 2017 09:15:50 -0400 Received: by mail-oi0-f65.google.com with SMTP id h9so8687906oia.4 for ; Wed, 27 Sep 2017 06:15:50 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <87wp4l6au9.fsf@kamboji.qca.qualcomm.com> References: <1506345709-4699-1-git-send-email-amitkarwar@gmail.com> <87wp4l6au9.fsf@kamboji.qca.qualcomm.com> From: Amitkumar Karwar Date: Wed, 27 Sep 2017 18:45:49 +0530 Message-ID: (sfid-20170927_151553_970976_6D29FB02) Subject: Re: [PATCH 2/3] rsi: sdio: Add WOWLAN support for S4 hibernate state To: Kalle Valo Cc: linux-wireless , Amitkumar Karwar , Prameela Rani Garnepudi , Karun Eagalapati Content-Type: text/plain; charset="UTF-8" Sender: linux-wireless-owner@vger.kernel.org List-ID: On Tue, Sep 26, 2017 at 3:27 PM, Kalle Valo wrote: > Amitkumar Karwar writes: > >> From: Karun Eagalapati >> >> We are disabling of interrupts from firmware in freeze handler. >> Also setting power management capability KEEP_MMC_POWER to make >> device wakeup for WoWLAN trigger. >> At restore, we observed a device reset on some platforms. Hence >> reloading of firmware and device initialization is performed. > > With "reloading of firmware and device initialization" you mean calling > rsi_mac80211_detach()? After rsi_mac80211_detach, we have a call for rsi_hal_device_init() in which reloading of firmware happens. > > void rsi_mac80211_detach(struct rsi_hw *adapter) > { > struct ieee80211_hw *hw = adapter->hw; > enum nl80211_band band; > > if (hw) { > ieee80211_stop_queues(hw); > ieee80211_unregister_hw(hw); > ieee80211_free_hw(hw); > } > > That looks like a quite heavy sledgehammer workaround to a resume > problem. Is it really the best way to handle this? I agree with you. I will appreciate if someone propose a better solution. Following are details about the problem. Connection remain alive after suspend(S4 state). System is resumed from S4 through GPIO pin after receiving magic packet. But SDIO doesn't work after this. We need to do perform SDIO reset and redownload the firmware. Mac80211 is under impression that connection is alive. We keep on getting mac80211 handler calls and data while firmware re-download is in progress. This leads to different race issues and occasionally kernel crashes. detaching from mac80211 solves the problem here. > > And even if that would be the right approach it needs to be properly > described in the commit log, a vague sentence in the end of a commit log > is not enough. Understood. I will add detailed description and send updated version if the patch is fine. Regards, Amitkumar Karwar