From patchwork Sat May 11 02:55:25 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shengjiu Wang X-Patchwork-Id: 13662246 Received: from inva020.nxp.com (inva020.nxp.com [92.121.34.13]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4132421A04; Sat, 11 May 2024 03:15:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=92.121.34.13 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715397314; cv=none; b=VZIgq5K8EUe00GcumMtTgm6CZQoIxhsNaWWiTH3MRiuTGYctKjk6mtJyPbFmzFYbf2aft7CEgXXh40QhTEDVBHfvGNZbiuwWv/v0wy88fiH2pJe/O0K4O0cbVmiUbTBOmgYPmpycMH0zqHejoXj3ZdQm6HCV11rlCiLRNHTwnWs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715397314; c=relaxed/simple; bh=7hKBsyDeJ3WJA3XhH1oHn62d0U8OLqzso5Esv3yvRT8=; h=From:To:Cc:Subject:Date:Message-Id; b=XyWz0qYKhCV2uAHhT7ZvAzYKFADoCDjWJc5NLx01MUj5VslGEg8Y5EaVzRYC5e02tkYKMmVh4Fu7YL35Y70C07vO2al+WHF3xDViaBF6OL1U+xwhj9BO0b6JApJrjBOpBXznVMRDesHYf5hqtG4y9+cF8feXYkJporTfI7IFfaA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=nxp.com; spf=pass smtp.mailfrom=nxp.com; arc=none smtp.client-ip=92.121.34.13 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=nxp.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=nxp.com Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 1C2EC1A02A7; Sat, 11 May 2024 05:15:04 +0200 (CEST) Received: from aprdc01srsp001v.ap-rdc01.nxp.com (aprdc01srsp001v.ap-rdc01.nxp.com [165.114.16.16]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 8116F1A07A8; Sat, 11 May 2024 05:15:03 +0200 (CEST) Received: from localhost.localdomain (shlinux2.ap.freescale.net [10.192.224.44]) by aprdc01srsp001v.ap-rdc01.nxp.com (Postfix) with ESMTP id BB0BA181D0FC; Sat, 11 May 2024 11:15:00 +0800 (+08) From: Shengjiu Wang To: ulf.hansson@linaro.org, heiko@sntech.de, u.kleine-koenig@pengutronix.de, geert+renesas@glider.be, rafael@kernel.org, linux-pm@vger.kernel.org, abelvesa@kernel.org, peng.fan@nxp.com, mturquette@baylibre.com, sboyd@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, imx@lists.linux.dev, shengjiu.wang@gmail.com, frank.li@nxp.com, mkl@pengutronix.de, linus.walleij@linaro.org Cc: linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v3] pmdomain: imx: gpcv2: Add delay after power up handshake Date: Sat, 11 May 2024 10:55:25 +0800 Message-Id: <1715396125-3724-1-git-send-email-shengjiu.wang@nxp.com> X-Mailer: git-send-email 2.7.4 X-Virus-Scanned: ClamAV using ClamSMTP Precedence: bulk X-Mailing-List: linux-clk@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: AudioMix BLK-CTRL on i.MX8MP encountered an accessing register issue after power up. [ 2.181035] Kernel panic - not syncing: Asynchronous SError Interrupt [ 2.181038] CPU: 1 PID: 48 Comm: kworker/u16:2 Not tainted 6.9.0-rc5-next-20240424-00003-g21cec88845c6 #171 [ 2.181047] Hardware name: NXP i.MX8MPlus EVK board (DT) [ 2.181050] Workqueue: events_unbound deferred_probe_work_func [ 2.181064] Call trace: [...] [ 2.181142] arm64_serror_panic+0x6c/0x78 [ 2.181149] do_serror+0x3c/0x70 [ 2.181157] el1h_64_error_handler+0x30/0x48 [ 2.181164] el1h_64_error+0x64/0x68 [ 2.181171] clk_imx8mp_audiomix_runtime_resume+0x34/0x44 [ 2.181183] __genpd_runtime_resume+0x30/0x80 [ 2.181195] genpd_runtime_resume+0x110/0x244 [ 2.181205] __rpm_callback+0x48/0x1d8 [ 2.181213] rpm_callback+0x68/0x74 [ 2.181224] rpm_resume+0x468/0x6c0 [ 2.181234] __pm_runtime_resume+0x50/0x94 [ 2.181243] pm_runtime_get_suppliers+0x60/0x8c [ 2.181258] __driver_probe_device+0x48/0x12c [ 2.181268] driver_probe_device+0xd8/0x15c [ 2.181278] __device_attach_driver+0xb8/0x134 [ 2.181290] bus_for_each_drv+0x84/0xe0 [ 2.181302] __device_attach+0x9c/0x188 [ 2.181312] device_initial_probe+0x14/0x20 [ 2.181323] bus_probe_device+0xac/0xb0 [ 2.181334] deferred_probe_work_func+0x88/0xc0 [ 2.181344] process_one_work+0x150/0x290 [ 2.181357] worker_thread+0x2f8/0x408 [ 2.181370] kthread+0x110/0x114 [ 2.181381] ret_from_fork+0x10/0x20 [ 2.181391] SMP: stopping secondary CPUs According to comments in power up handshake: /* request the ADB400 to power up */ if (domain->bits.hskreq) { regmap_update_bits(domain->regmap, domain->regs->hsk, domain->bits.hskreq, domain->bits.hskreq); /* * ret = regmap_read_poll_timeout(domain->regmap, domain->regs->hsk, reg_val, * (reg_val & domain->bits.hskack), 0, * USEC_PER_MSEC); * Technically we need the commented code to wait handshake. But that needs * the BLK-CTL module BUS clk-en bit being set. * * There is a separate BLK-CTL module and we will have such a driver for it, * that driver will set the BUS clk-en bit and handshake will be triggered * automatically there. Just add a delay and suppose the handshake finish * after that. */ } The BLK-CTL module needs to add delay to wait for a handshake request finished. For some BLK-CTL module (eg. AudioMix on i.MX8MP) doesn't have BUS clk-en bit, it is better to add delay in this driver, as the BLK-CTL module doesn't need to care about how it is powered up. regmap_read_bypassed() is to make sure the above write IO transaction already reaches target before udelay(). Fixes: 1496dd413b2e ("clk: imx: imx8mp: Add pm_runtime support for power saving") Reported-by: Francesco Dolcini Closes: https://lore.kernel.org/all/66293535.170a0220.21fe.a2e7@mx.google.com/ Suggested-by: Frank Li Signed-off-by: Shengjiu Wang Tested-by: Adam Ford Tested-by: Alexander Stein --- changes in v3: - move change to gpcv2.c, as it is more reasonable to let power driver to handle such power issue, suggested by Frank Li changes in v2: - reduce size of panic log in commit message drivers/pmdomain/imx/gpcv2.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/pmdomain/imx/gpcv2.c b/drivers/pmdomain/imx/gpcv2.c index 4b828d74a606..856eaac0ec14 100644 --- a/drivers/pmdomain/imx/gpcv2.c +++ b/drivers/pmdomain/imx/gpcv2.c @@ -393,6 +393,17 @@ static int imx_pgc_power_up(struct generic_pm_domain *genpd) * automatically there. Just add a delay and suppose the handshake finish * after that. */ + + /* + * For some BLK-CTL module (eg. AudioMix on i.MX8MP) doesn't have BUS + * clk-en bit, it is better to add delay here, as the BLK-CTL module + * doesn't need to care about how it is powered up. + * + * regmap_read_bypassed() is to make sure the above write IO transaction + * already reaches target before udelay() + */ + regmap_read_bypassed(domain->regmap, domain->regs->hsk, ®_val); + udelay(5); } /* Disable reset clocks for all devices in the domain */