From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D0622C43470 for ; Mon, 10 May 2021 12:05:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ACC9E613C9 for ; Mon, 10 May 2021 12:05:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238678AbhEJMFH (ORCPT ); Mon, 10 May 2021 08:05:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:45768 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236348AbhEJLHy (ORCPT ); Mon, 10 May 2021 07:07:54 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 00B656197D; Mon, 10 May 2021 11:00:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620644412; bh=P1eG6K6NN2oEpjR+HPDeABt2ux4J8L1hfYpC4vevT14=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wI0AwBWiLXu1Z2FmjM34KfRosKBGmfvz91q63EIQBO4i8NQI5b74nB7hBAx4UR1sJ RSQo8SgRXZs/0WmnDF3qZGpZgD33RmAN8v95m4RBdYJJfw1XpFQZZ7JPn3CdYe4eG9 +0YPYOHoKt00S/VdG/zbhsKSLvU8kZHRuo5TlGWw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Loic Poulain , Manivannan Sadhasivam , Sasha Levin Subject: [PATCH 5.12 071/384] bus: mhi: pci_generic: No-Op for device_wake operations Date: Mon, 10 May 2021 12:17:40 +0200 Message-Id: <20210510102017.231071083@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210510102014.849075526@linuxfoundation.org> References: <20210510102014.849075526@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: Loic Poulain [ Upstream commit e3e5e6508fc1c0e98a5a264853713dd30a60e5e5 ] The wake_db register presence is highly speculative and can fuze MHI devices. Indeed, currently the wake_db register address is defined at entry 127 of the 'Channel doorbell array', thus writing to this address is equivalent to ringing the doorbell for channel 127, causing trouble with some devics (e.g. SDX24 based modems) that get an unexpected channel 127 doorbell interrupt. This change fixes that issue by setting wake get/put as no-op for pci_generic devices. The wake device sideband mechanism seems really specific to each device, and is AFAIK not defined by the MHI spec. It also removes zeroing initialization of wake_db register during MMIO initialization, the register being set via wake_get/put accessors few cycles later during M0 transition. Signed-off-by: Loic Poulain Reviewed-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/1614971808-22156-4-git-send-email-loic.poulain@linaro.org Signed-off-by: Manivannan Sadhasivam Signed-off-by: Sasha Levin --- drivers/bus/mhi/core/init.c | 2 -- drivers/bus/mhi/pci_generic.c | 18 ++++++++++++++++++ 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c index 419d026197ad..6cb0d67fc921 100644 --- a/drivers/bus/mhi/core/init.c +++ b/drivers/bus/mhi/core/init.c @@ -508,8 +508,6 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl) /* Setup wake db */ mhi_cntrl->wake_db = base + val + (8 * MHI_DEV_WAKE_DB); - mhi_write_reg(mhi_cntrl, mhi_cntrl->wake_db, 4, 0); - mhi_write_reg(mhi_cntrl, mhi_cntrl->wake_db, 0, 0); mhi_cntrl->wake_set = false; /* Setup channel db address for each channel in tre_ring */ diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c index 20673a4b4a3c..356c19ce4bbf 100644 --- a/drivers/bus/mhi/pci_generic.c +++ b/drivers/bus/mhi/pci_generic.c @@ -230,6 +230,21 @@ static void mhi_pci_status_cb(struct mhi_controller *mhi_cntrl, } } +static void mhi_pci_wake_get_nop(struct mhi_controller *mhi_cntrl, bool force) +{ + /* no-op */ +} + +static void mhi_pci_wake_put_nop(struct mhi_controller *mhi_cntrl, bool override) +{ + /* no-op */ +} + +static void mhi_pci_wake_toggle_nop(struct mhi_controller *mhi_cntrl) +{ + /* no-op */ +} + static bool mhi_pci_is_alive(struct mhi_controller *mhi_cntrl) { struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev); @@ -433,6 +448,9 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) mhi_cntrl->status_cb = mhi_pci_status_cb; mhi_cntrl->runtime_get = mhi_pci_runtime_get; mhi_cntrl->runtime_put = mhi_pci_runtime_put; + mhi_cntrl->wake_get = mhi_pci_wake_get_nop; + mhi_cntrl->wake_put = mhi_pci_wake_put_nop; + mhi_cntrl->wake_toggle = mhi_pci_wake_toggle_nop; err = mhi_pci_claim(mhi_cntrl, info->bar_num, DMA_BIT_MASK(info->dma_data_width)); if (err) -- 2.30.2