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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD281C433F5 for ; Mon, 24 Jan 2022 21:27:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1451822AbiAXVXj (ORCPT ); Mon, 24 Jan 2022 16:23:39 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:46816 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1442867AbiAXUzf (ORCPT ); Mon, 24 Jan 2022 15:55:35 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7B015612C3; Mon, 24 Jan 2022 20:55:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 55A18C340EA; Mon, 24 Jan 2022 20:55:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643057733; bh=XmunwkHp3uSTDer0TGSDoR8vFkcsn6YyKg9JSHU7/wM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Aqaz7oDnQ3K3IcyldeYn7nz7Wt7W87rLKQjeBJ0h10gdNDmQE5VK/xpQdztjTB0DB wRPnGJbH31wmkcjTLTO9RFJJgvmz0E9f45hxtd9tkyk3UhAfjPm15cVqfNWbwDm6D/ CV87PIsZWxXRI7mjrR85aYKAQPiQyrRjr7kxVn64= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Aleksander Morgado , Thomas Perrot , Manivannan Sadhasivam Subject: [PATCH 5.16 0062/1039] bus: mhi: core: Fix race while handling SYS_ERR at power up Date: Mon, 24 Jan 2022 19:30:51 +0100 Message-Id: <20220124184127.234835641@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184125.121143506@linuxfoundation.org> References: <20220124184125.121143506@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Manivannan Sadhasivam commit d651ce8e917fa1bf6cfab8dca74c512edffc35d3 upstream. During SYS_ERR condition, as a response to the MHI_RESET from host, some devices tend to issue BHI interrupt without clearing the SYS_ERR state in the device. This creates a race condition and causes a failure in booting up the device. The issue is seen on the Sierra Wireless EM9191 modem during SYS_ERR handling in mhi_async_power_up(). Once the host detects that the device is in SYS_ERR state, it issues MHI_RESET and waits for the device to process the reset request. During this time, the device triggers the BHI interrupt to the host without clearing SYS_ERR condition. So the host starts handling the SYS_ERR condition again. To fix this issue, let's register the IRQ handler only after handling the SYS_ERR check to avoid getting spurious IRQs from the device. Fixes: e18d4e9fa79b ("bus: mhi: core: Handle syserr during power_up") Cc: stable@vger.kernel.org Reported-by: Aleksander Morgado Tested-by: Aleksander Morgado Tested-by: Thomas Perrot Signed-off-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/20211216081227.237749-8-manivannan.sadhasivam@linaro.org Signed-off-by: Greg Kroah-Hartman --- drivers/bus/mhi/core/pm.c | 35 ++++++++++++----------------------- 1 file changed, 12 insertions(+), 23 deletions(-) --- a/drivers/bus/mhi/core/pm.c +++ b/drivers/bus/mhi/core/pm.c @@ -1053,7 +1053,7 @@ int mhi_async_power_up(struct mhi_contro enum mhi_ee_type current_ee; enum dev_st_transition next_state; struct device *dev = &mhi_cntrl->mhi_dev->dev; - u32 val; + u32 interval_us = 25000; /* poll register field every 25 milliseconds */ int ret; dev_info(dev, "Requested to power ON\n"); @@ -1070,10 +1070,6 @@ int mhi_async_power_up(struct mhi_contro mutex_lock(&mhi_cntrl->pm_mutex); mhi_cntrl->pm_state = MHI_PM_DISABLE; - ret = mhi_init_irq_setup(mhi_cntrl); - if (ret) - goto error_setup_irq; - /* Setup BHI INTVEC */ write_lock_irq(&mhi_cntrl->pm_lock); mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0); @@ -1087,7 +1083,7 @@ int mhi_async_power_up(struct mhi_contro dev_err(dev, "%s is not a valid EE for power on\n", TO_MHI_EXEC_STR(current_ee)); ret = -EIO; - goto error_async_power_up; + goto error_exit; } state = mhi_get_mhi_state(mhi_cntrl); @@ -1096,20 +1092,12 @@ int mhi_async_power_up(struct mhi_contro if (state == MHI_STATE_SYS_ERR) { mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET); - ret = wait_event_timeout(mhi_cntrl->state_event, - MHI_PM_IN_FATAL_STATE(mhi_cntrl->pm_state) || - mhi_read_reg_field(mhi_cntrl, - mhi_cntrl->regs, - MHICTRL, - MHICTRL_RESET_MASK, - MHICTRL_RESET_SHIFT, - &val) || - !val, - msecs_to_jiffies(mhi_cntrl->timeout_ms)); - if (!ret) { - ret = -EIO; + ret = mhi_poll_reg_field(mhi_cntrl, mhi_cntrl->regs, MHICTRL, + MHICTRL_RESET_MASK, MHICTRL_RESET_SHIFT, 0, + interval_us); + if (ret) { dev_info(dev, "Failed to reset MHI due to syserr state\n"); - goto error_async_power_up; + goto error_exit; } /* @@ -1119,6 +1107,10 @@ int mhi_async_power_up(struct mhi_contro mhi_write_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_INTVEC, 0); } + ret = mhi_init_irq_setup(mhi_cntrl); + if (ret) + goto error_exit; + /* Transition to next state */ next_state = MHI_IN_PBL(current_ee) ? DEV_ST_TRANSITION_PBL : DEV_ST_TRANSITION_READY; @@ -1131,10 +1123,7 @@ int mhi_async_power_up(struct mhi_contro return 0; -error_async_power_up: - mhi_deinit_free_irq(mhi_cntrl); - -error_setup_irq: +error_exit: mhi_cntrl->pm_state = MHI_PM_DISABLE; mutex_unlock(&mhi_cntrl->pm_mutex);