From patchwork Wed May 27 13:55:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Lindgren X-Patchwork-Id: 11573057 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 0A81A90 for ; Wed, 27 May 2020 13:56:05 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DD0A4208C3 for ; Wed, 27 May 2020 13:56:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="aGf74v/J" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DD0A4208C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=atomide.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=T62mhTJ14vmlnYyhWVaL0NE54AcUcewq5skTLUa0hAY=; b=aGf74v/JBFzIA6 mLLOL6noN7THZgE+WnAcvSQTNAthcL9A9bkkOwV6VaXVnJGzIapFtYX00wojcd0rilW9eBfzr2Rmz KfwPD5Z4zMz1TwbswCAQdMA1qNNcps8EbepvoLmdFDIH5TPHI6JRyvuHoJwTD02qRsr6ETvIzV44y qGXiwl37REDFabOHznf1L726ts7iAZYuiv3JqacfNRdJ2QQcxW8MD1itrz5EgbNnzRpdx574owo57 VW/edcMzVg5ejSaY16+L5akxuxXF5kZLr5auK53XqJvrPA3OMM+LQlcFgxF2ZFd+veN0JJl85lKLf yI//dGfmBUhiJO2TLO4w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jdwXE-0000m0-SM; Wed, 27 May 2020 13:55:56 +0000 Received: from muru.com ([72.249.23.125]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jdwXB-0000km-CZ for linux-arm-kernel@lists.infradead.org; Wed, 27 May 2020 13:55:54 +0000 Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id E5A1780DB; Wed, 27 May 2020 13:56:39 +0000 (UTC) From: Tony Lindgren To: linux-omap@vger.kernel.org Subject: [PATCH] bus: ti-sysc: Flush posted write on enable and disable Date: Wed, 27 May 2020 06:55:39 -0700 Message-Id: <20200527135539.49059-1-tony@atomide.com> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200527_065553_467092_7B0A473B X-CRM114-Status: GOOD ( 10.38 ) X-Spam-Score: 0.0 (/) X-Spam-Report: SpamAssassin version 3.4.4 on bombadil.infradead.org summary: Content analysis details: (0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [72.249.23.125 listed in list.dnswl.org] 0.0 SPF_NONE SPF: sender does not publish an SPF Record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Nishanth Menon , Tero Kristo , Dave Gerlach , Keerthy , linux-kernel@vger.kernel.org, "Andrew F . Davis" , Peter Ujfalusi , Faiz Abbas , Greg Kroah-Hartman , Suman Anna , linux-arm-kernel@lists.infradead.org, Roger Quadros Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Looks like we're missing flush of posted write after module enable and disable. I've seen occasional errors accessing various modules, and it is suspected that the lack of posted writes can also cause random reboots. The errors we can see are similar to the one below from spi for example: 44000000.ocp:L3 Custom Error: MASTER MPU TARGET L4CFG (Read): Data Access in User mode during Functional access ... mcspi_wait_for_reg_bit omap2_mcspi_transfer_one spi_transfer_one_message ... We also want to also flush posted write for disable. The clkctrl clock disable happens after module disable, and we don't want to have the module potentially stay active while we're trying to disable the clock. Fixes: d59b60564cbf ("bus: ti-sysc: Add generic enable/disable functions") Signed-off-by: Tony Lindgren --- drivers/bus/ti-sysc.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c --- a/drivers/bus/ti-sysc.c +++ b/drivers/bus/ti-sysc.c @@ -991,6 +991,9 @@ static int sysc_enable_module(struct device *dev) sysc_write_sysconfig(ddata, reg); } + /* Flush posted write */ + sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]); + if (ddata->module_enable_quirk) ddata->module_enable_quirk(ddata); @@ -1071,6 +1074,9 @@ static int sysc_disable_module(struct device *dev) reg |= 1 << regbits->autoidle_shift; sysc_write_sysconfig(ddata, reg); + /* Flush posted write */ + sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]); + return 0; }