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=-6.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 DB5E6C4741F for ; Fri, 30 Oct 2020 15:01:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 886C022246 for ; Fri, 30 Oct 2020 15:01:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="uEdmCX24" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726948AbgJ3PBM (ORCPT ); Fri, 30 Oct 2020 11:01:12 -0400 Received: from z5.mailgun.us ([104.130.96.5]:11695 "EHLO z5.mailgun.us" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726178AbgJ3PAa (ORCPT ); Fri, 30 Oct 2020 11:00:30 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1604069973; h=Message-ID: References: In-Reply-To: Subject: Cc: To: From: Date: Content-Transfer-Encoding: Content-Type: MIME-Version: Sender; bh=NRiAvEzduLH4Fyb+nC9qHYSc/q8IvoaoKJXFIDpgOag=; b=uEdmCX24MegZT0stROoDcWddCJOxx/P6O/HhKTg5pAM6aVqIRgb23qqUhosEk7/oAfuJ0x+0 II0tpPi4L2uZq4OnU70In/um6T/5IwTA6loCXdqqJ33Jt1WY5WWmdr48C89a+8lxTJCtWkrI 1E064YMT7gI/knG+CSDA/DC5FPc= X-Mailgun-Sending-Ip: 104.130.96.5 X-Mailgun-Sid: WyI3ZjU0NiIsICJsaW51eC1tZWRpYUB2Z2VyLmtlcm5lbC5vcmciLCAiYmU5ZTRhIl0= Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n07.prod.us-west-2.postgun.com with SMTP id 5f9c2a54b01cad7dbfeeadbe (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 30 Oct 2020 14:59:32 GMT Sender: rojay=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 8E71FC433C6; Fri, 30 Oct 2020 14:59:32 +0000 (UTC) Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: rojay) by smtp.codeaurora.org (Postfix) with ESMTPSA id E8E1BC433C9; Fri, 30 Oct 2020 14:59:31 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Fri, 30 Oct 2020 20:29:31 +0530 From: rojay@codeaurora.org To: Stephen Boyd Cc: wsa@kernel.org, dianders@chromium.org, saiprakash.ranjan@codeaurora.org, gregkh@linuxfoundation.org, mka@chromium.org, akashast@codeaurora.org, msavaliy@qti.qualcomm.com, skakit@codeaurora.org, vkaur@codeaurora.org, pyarlaga@codeaurora.org, rnayak@codeaurora.org, agross@kernel.org, bjorn.andersson@linaro.org, linux-arm-msm@vger.kernel.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, sumit.semwal@linaro.org, linux-media@vger.kernel.org Subject: Re: [PATCH V5 3/3] i2c: i2c-qcom-geni: Add shutdown callback for i2c In-Reply-To: <160168919332.310579.15311671258384969025@swboyd.mtv.corp.google.com> References: <20201001084425.23117-1-rojay@codeaurora.org> <20201001084425.23117-4-rojay@codeaurora.org> <160168919332.310579.15311671258384969025@swboyd.mtv.corp.google.com> Message-ID: <17edaa6ceded98199a6f94a505cbd436@codeaurora.org> X-Sender: rojay@codeaurora.org User-Agent: Roundcube Webmail/1.3.9 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Stephen, On 2020-10-03 07:09, Stephen Boyd wrote: > Quoting Roja Rani Yarubandi (2020-10-01 01:44:25) >> diff --git a/drivers/i2c/busses/i2c-qcom-geni.c >> b/drivers/i2c/busses/i2c-qcom-geni.c >> index aee2a1dd2c62..56d3fbfe7eb6 100644 >> --- a/drivers/i2c/busses/i2c-qcom-geni.c >> +++ b/drivers/i2c/busses/i2c-qcom-geni.c >> @@ -380,6 +380,36 @@ static void geni_i2c_tx_msg_cleanup(struct >> geni_i2c_dev *gi2c, >> } >> } >> >> +static void geni_i2c_stop_xfer(struct geni_i2c_dev *gi2c) >> +{ >> + int ret; >> + u32 geni_status; >> + unsigned long flags; >> + struct i2c_msg *cur; >> + >> + /* Resume device, runtime suspend can happen anytime during >> transfer */ >> + ret = pm_runtime_get_sync(gi2c->se.dev); >> + if (ret < 0) { >> + dev_err(gi2c->se.dev, "Failed to resume device: %d\n", >> ret); >> + return; >> + } >> + >> + spin_lock_irqsave(&gi2c->lock, flags); > > We grab the lock here. > >> + geni_status = readl_relaxed(gi2c->se.base + SE_GENI_STATUS); >> + if (!(geni_status & M_GENI_CMD_ACTIVE)) >> + goto out; >> + >> + cur = gi2c->cur; >> + geni_i2c_abort_xfer(gi2c); > > But it looks like this function takes the lock again? Did you test this > with lockdep enabled? It should hang even without lockdep, so it seems > like this path of code has not been tested. > Tested with lockdep enabled, and fixed the unsafe lock order issue here. And to be more proper moved spin_lock/unlock to cleanup functions. >> + if (cur->flags & I2C_M_RD) >> + geni_i2c_rx_msg_cleanup(gi2c, cur); >> + else >> + geni_i2c_tx_msg_cleanup(gi2c, cur); >> + spin_unlock_irqrestore(&gi2c->lock, flags); >> +out: >> + pm_runtime_put_sync_suspend(gi2c->se.dev); >> +} >> + >> static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct >> i2c_msg *msg, >> u32 m_param) >> {