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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 40AFAC433E0 for ; Wed, 10 Mar 2021 13:30:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A1FA64FFA for ; Wed, 10 Mar 2021 13:30:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234308AbhCJN35 (ORCPT ); Wed, 10 Mar 2021 08:29:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234213AbhCJN3i (ORCPT ); Wed, 10 Mar 2021 08:29:38 -0500 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9923EC061760 for ; Wed, 10 Mar 2021 05:29:38 -0800 (PST) Received: by mail-pf1-x435.google.com with SMTP id 18so12054273pfo.6 for ; Wed, 10 Mar 2021 05:29:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=XRmDUhp4HTrIlS6k+9mhT1AI9vqeFpX1fwPqd8M1lVQ=; b=seD0W0t7sZx41+bQkMZwFt27wPVyBnsHq1oh1YcXM3oBTqwoIvOysKQiuHhSfikoVw wbmI5p8LHAYrKbRui0Xc5ZMvGA6My1E/xBvh9xw84WbTSFWuC2QCl+aF8f1DuTtDbIys n+3ZH7ONUHECdWwiKRsXN/kfijAwpeJSaRmRhbgNlEENagQsVjgNDvkp+b4j2bDZKCua B+16XnO8Iu4HtdkcILfdFdOoUHZ4DR71dXarpH5jYfQm70obkw+D6sZDBgNeKGwWwuWS r77TkIQROb2C/urS4UxFZUMQr9VlBXVeboFighAE7wmMHthGDr5zeFLfl/bVbcWo1Ak3 QxVA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=XRmDUhp4HTrIlS6k+9mhT1AI9vqeFpX1fwPqd8M1lVQ=; b=kQjGBSNYu7mqbGyokA85DV2CEcm1xAnOP2CCkgk3XlVOV+KxGAbABYQnCXeHOKTVCc 2Z1VF0poyxEh3mqHuQE3cloBZ1DycMffNsFnJ2W7TTaJKERNsJz1kqHecbYskzuPtbvG wNndqxf50aawY4C5tUbHKaLyqwQ3iz0mT9Ji3hLSG/3IK7djDFb6WS2mPEWyNFBSgklf oLAUgz+aNrfjKae87qztbiOW4aQXnkTvi5rmFZjjN1WlsqUHggn5MiRr3qrKOCMet8w8 SQ6jXlYb/XjJ3mhwkzEJ1YPGQt2uEcTVwgR4AiF2B+a68LQSPV9O9LRkPH9G+ahJFtE6 fv7w== X-Gm-Message-State: AOAM531eMuUlsswrWrzm6mRuZojAaAGBc9of9iNUFtAs1q7zmxax7Jh5 J8sllkpdzKMUSIDNSvVWGO7q X-Google-Smtp-Source: ABdhPJx1Bow11o4JqeSq/0Q280CLsTpk/Vhvv3F7osrYWTURym7B+2HRitS16bOAq/3z1ecCeozRCA== X-Received: by 2002:a65:5288:: with SMTP id y8mr2762460pgp.105.1615382977996; Wed, 10 Mar 2021 05:29:37 -0800 (PST) Received: from thinkpad ([103.66.79.59]) by smtp.gmail.com with ESMTPSA id y19sm17947761pfo.0.2021.03.10.05.29.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Mar 2021 05:29:37 -0800 (PST) Date: Wed, 10 Mar 2021 18:59:33 +0530 From: Manivannan Sadhasivam To: Loic Poulain Cc: hemantk@codeaurora.org, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH v3 4/6] mhi: pci_generic: No-Op for device_wake operations Message-ID: <20210310132933.GA30275@thinkpad> References: <1614971808-22156-1-git-send-email-loic.poulain@linaro.org> <1614971808-22156-4-git-send-email-loic.poulain@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1614971808-22156-4-git-send-email-loic.poulain@linaro.org> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Fri, Mar 05, 2021 at 08:16:46PM +0100, Loic Poulain wrote: > 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 Thanks, Mani > --- > v2: reword commit message > v3: no change > > 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 2159dbc..32eb90f 100644 > --- a/drivers/bus/mhi/core/init.c > +++ b/drivers/bus/mhi/core/init.c > @@ -510,8 +510,6 @@ 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); I'm okay with the change since this is not documented anywhere. And if this is required for any cases, can be done in the controller driver later. > 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 c274e65..4685a83 100644 > --- a/drivers/bus/mhi/pci_generic.c > +++ b/drivers/bus/mhi/pci_generic.c > @@ -312,6 +312,21 @@ 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); > @@ -515,6 +530,9 @@ 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) > -- > 2.7.4 >