From patchwork Mon Oct 5 05:59:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maulik Shah X-Patchwork-Id: 11816147 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6D6EE6CB for ; Mon, 5 Oct 2020 06:00:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4CB362080A for ; Mon, 5 Oct 2020 06:00:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="fhhKPP7L" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725853AbgJEGA4 (ORCPT ); Mon, 5 Oct 2020 02:00:56 -0400 Received: from m42-4.mailgun.net ([69.72.42.4]:48527 "EHLO m42-4.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725880AbgJEGAz (ORCPT ); Mon, 5 Oct 2020 02:00:55 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1601877654; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=T3DkxwcHdksC0LWeDDahSysoPZBKI1uqfWg0787tmsE=; b=fhhKPP7LQbvHT4lDPQm7lwDZX2X8CjCrqINNTzAFdSGZJn5Nb+NaXGINI18dLisW4/B2FsXJ GZqotHttUWAqud08AlthXpbn5oA/XMsqxRPw1YX2fnfIZQ4mhnhu7Y87G4zmefbbdj2QVGA4 ZMosYFI7pmp/Ov2m08JznQG0v14= X-Mailgun-Sending-Ip: 69.72.42.4 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n01.prod.us-east-1.postgun.com with SMTP id 5f7ab6753711fec7b12314d3 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Mon, 05 Oct 2020 06:00:21 GMT Sender: mkshah=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id ED5CAC43387; Mon, 5 Oct 2020 06:00:20 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=ALL_TRUSTED,BAYES_00,SPF_FAIL, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mkshah-linux.qualcomm.com (unknown [202.46.22.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: mkshah) by smtp.codeaurora.org (Postfix) with ESMTPSA id 853A7C433FE; Mon, 5 Oct 2020 06:00:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 853A7C433FE Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=mkshah@codeaurora.org From: Maulik Shah To: agross@kernel.org, bjorn.andersson@linaro.org Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, ulf.hansson@linaro.org, swboyd@chromium.org, dianders@chromium.org, rnayak@codeaurora.org, ilina@codeaurora.org, lsrao@codeaurora.org, Maulik Shah , Sai Prakash Ranjan , John Stultz , Stephen Rothwell Subject: [RESEND v2 1/2] Revert "drivers: qcom: rpmh-rsc: Use rcuidle tracepoints for rpmh" Date: Mon, 5 Oct 2020 11:29:55 +0530 Message-Id: <1601877596-32676-2-git-send-email-mkshah@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1601877596-32676-1-git-send-email-mkshah@codeaurora.org> References: <1601877596-32676-1-git-send-email-mkshah@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Commit efde2659b0fe ("drivers: qcom: rpmh-rsc: Use rcuidle tracepoints for rpmh") was written to fix a bug seen in an unmerged series that implemented a struct generic_pm_domain::power_off() callback calling rpmh_flush(). See stack trace below. Call trace: dump_backtrace+0x0/0x174 show_stack+0x20/0x2c dump_stack+0xc8/0x124 lockdep_rcu_suspicious+0xe4/0x104 __tcs_buffer_write+0x230/0x2d0 rpmh_rsc_write_ctrl_data+0x210/0x270 rpmh_flush+0x84/0x24c rpmh_domain_power_off+0x78/0x98 _genpd_power_off+0x40/0xc0 genpd_power_off+0x168/0x208 Later the final merged solution is to use CPU PM notification to invoke rpmh_flush() and power_off() callback of genpd is not implemented in the driver. CPU PM notifiers are run with RCU enabled/watching (see cpu_pm_notify() and how it calls rcu_irq_enter_irqson() before calling the notifiers). Remove this change since RCU will not be idle during CPU PM notifications hence not required to use _rcuidle tracepoint. Using _rcuidle tracepoint prevented rpmh driver to be loadable module as these are not exported symbols. This reverts commit efde2659b0fe835732047357b2902cca14f054d9. Cc: Sai Prakash Ranjan Cc: John Stultz Cc: Stephen Rothwell Reviewed-by: Stephen Boyd Reviewed-by: Sai Prakash Ranjan Reviewed-by: Ulf Hansson Signed-off-by: Maulik Shah Reviewed-by: Bjorn Andersson --- drivers/soc/qcom/rpmh-rsc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c index a297911..35a7a50 100644 --- a/drivers/soc/qcom/rpmh-rsc.c +++ b/drivers/soc/qcom/rpmh-rsc.c @@ -497,7 +497,7 @@ static void __tcs_buffer_write(struct rsc_drv *drv, int tcs_id, int cmd_id, write_tcs_cmd(drv, RSC_DRV_CMD_MSGID, tcs_id, j, msgid); write_tcs_cmd(drv, RSC_DRV_CMD_ADDR, tcs_id, j, cmd->addr); write_tcs_cmd(drv, RSC_DRV_CMD_DATA, tcs_id, j, cmd->data); - trace_rpmh_send_msg_rcuidle(drv, tcs_id, j, msgid, cmd); + trace_rpmh_send_msg(drv, tcs_id, j, msgid, cmd); } write_tcs_reg(drv, RSC_DRV_CMD_WAIT_FOR_CMPL, tcs_id, cmd_complete);