Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9FD5BC433FE for ; Mon, 15 Nov 2021 17:26:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E90E63285 for ; Mon, 15 Nov 2021 17:26:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238073AbhKOR2v (ORCPT ); Mon, 15 Nov 2021 12:28:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:51016 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231330AbhKOROo (ORCPT ); Mon, 15 Nov 2021 12:14:44 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1E78C61BD2; Mon, 15 Nov 2021 17:11:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1636996268; bh=lmyTwlSTaOA3RuONXtbyQwUrrHnruOYLE2E5shgqJac=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oK/8HDCcsFXLnjOggaSojeDaJfPxc4RYJVN6uqmH3jFxXtCN0eynQwgspX1iLZnaS Te7c6I16g11xxsYv2YD72fn45VNkViK77xYanKooeE2g0Ahd22V59TlAr6qploMFFn 7GxDezZdjUUPu+fu58Jm2C8KHY3yFtPFd8ACDHkM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?UTF-8?q?Jonas=20Dre=C3=9Fler?= , Kalle Valo Subject: [PATCH 5.4 078/355] mwifiex: Read a PCI register after writing the TX ring write pointer Date: Mon, 15 Nov 2021 18:00:02 +0100 Message-Id: <20211115165316.328535509@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165313.549179499@linuxfoundation.org> References: <20211115165313.549179499@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jonas Dreßler commit e5f4eb8223aa740237cd463246a7debcddf4eda1 upstream. On the 88W8897 PCIe+USB card the firmware randomly crashes after setting the TX ring write pointer. The issue is present in the latest firmware version 15.68.19.p21 of the PCIe+USB card. Those firmware crashes can be worked around by reading any PCI register of the card after setting that register, so read the PCI_VENDOR_ID register here. The reason this works is probably because we keep the bus from entering an ASPM state for a bit longer, because that's what causes the cards firmware to crash. This fixes a bug where during RX/TX traffic and with ASPM L1 substates enabled (the specific substates where the issue happens appear to be platform dependent), the firmware crashes and eventually a command timeout appears in the logs. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=109681 Cc: stable@vger.kernel.org Signed-off-by: Jonas Dreßler Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20211011133224.15561-2-verdre@v0yd.nl Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/marvell/mwifiex/pcie.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/drivers/net/wireless/marvell/mwifiex/pcie.c +++ b/drivers/net/wireless/marvell/mwifiex/pcie.c @@ -1326,6 +1326,14 @@ mwifiex_pcie_send_data(struct mwifiex_ad ret = -1; goto done_unmap; } + + /* The firmware (latest version 15.68.19.p21) of the 88W8897 PCIe+USB card + * seems to crash randomly after setting the TX ring write pointer when + * ASPM powersaving is enabled. A workaround seems to be keeping the bus + * busy by reading a random register afterwards. + */ + mwifiex_read_reg(adapter, PCI_VENDOR_ID, &rx_val); + if ((mwifiex_pcie_txbd_not_full(card)) && tx_param->next_pkt_len) { /* have more packets and TxBD still can hold more */