From patchwork Tue Sep 2 23:37:14 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 4829351 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id E36989F32F for ; Tue, 2 Sep 2014 23:37:50 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E901F201F2 for ; Tue, 2 Sep 2014 23:37:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D026B201E4 for ; Tue, 2 Sep 2014 23:37:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753784AbaIBXha (ORCPT ); Tue, 2 Sep 2014 19:37:30 -0400 Received: from mail-pd0-f178.google.com ([209.85.192.178]:47612 "EHLO mail-pd0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751364AbaIBXh3 (ORCPT ); Tue, 2 Sep 2014 19:37:29 -0400 Received: by mail-pd0-f178.google.com with SMTP id y13so9806722pdi.9 for ; Tue, 02 Sep 2014 16:37:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id; bh=p91ykb4hPBw1ZKMJyGn72HpUzsPuIs40S837ClAJdzw=; b=K13Lry3N+2tFJjqZ151QWuuWok9zLRNwFavD29WjdtDUU8WXylLacsxFOhL02/Yuwm u5lcpYUj7nHcWG7xiDi7EEN84duc4GWLMX7FFEn9/Cu6yV1tXZhYoVPS7gCvyYh7Peeq vVXTxWLg5OMaBNpB1b6mtzin2MkGNQZVPRhGI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=p91ykb4hPBw1ZKMJyGn72HpUzsPuIs40S837ClAJdzw=; b=Hbez4eko/V00XNZHQFDK8k/Kdat4CqxCwfdXwxcHaEA7k1n282tNSPx1ZXA5c+uLmX Dtwj5tpgCAtH5aiz4L6nIOP8irG/DB41mFRjdRoEROtbLTAJ1XWMgX3xp3Hh+BxK5g+7 Hl6AnjbkNp7hEaOACP8m2SeMV856OO2o/scHAubZC8hl90gAaorrIccLC/HpXDUU/RiT Cfk8InPOqJelNfdO6vhGci9R8krrWykGadwS0adh22/DPkWPcw9fwifOun33vxFkhqCz 8lvFAQGZrQdctfiQyiCVg/+YeHv1ML8atBaOFcG9P9Bj3YPeQ0Eavjh5tbZmGeythH53 XfBw== X-Gm-Message-State: ALoCoQmJPzxJMwhhdkBoX5AE4ObnDcXShm3dgBV1hbD4yzKhR+FUBiDr0LOx+4E9L1B6RVoYx+5S X-Received: by 10.70.131.101 with SMTP id ol5mr40272019pdb.77.1409701049176; Tue, 02 Sep 2014 16:37:29 -0700 (PDT) Received: from tictac.mtv.corp.google.com (tictac.mtv.corp.google.com [172.22.162.15]) by mx.google.com with ESMTPSA id pm1sm7013628pdb.58.2014.09.02.16.37.27 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 02 Sep 2014 16:37:28 -0700 (PDT) From: Doug Anderson To: Seungwon Jeon , Jaehoon Chung , Ulf Hansson Cc: linux-arm-kernel@lists.infradead.org, Addy Ke , Sonny Rao , Doug Anderson , chris@printf.net, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] mmc: dw_mmc: Don't enable interrupts until we're ready Date: Tue, 2 Sep 2014 16:37:14 -0700 Message-Id: <1409701034-28526-1-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 2.1.0.rc2.206.gedb03e5 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Spam-Status: No, score=-8.5 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,T_DKIM_INVALID,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On dw_mmc there's a small race if you happen to get a card detect interrupt at just the wrong time during probe. You may have enabled the interrupt but host->slot[0] may be NULL. Fix the race by enabling interrupts all the way at the end of the probe. We can also use free_irq() instead of dw_mmc specific masking to mask the IRQ at removal time. Note that since we're now managing freeing of the irq ourselves, there's no need to use devm. FYI, the crash would look like: dwmmc_rockchip ff0c0000.dwmmc: DW MMC controller at irq 64, 32 bit host data width, 256 deep fifo Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = c0004000 [00000000] *pgd=00000000 ... ... [] (dw_mci_work_routine_card) from [] (process_one_work+0x260/0x3c4) [] (process_one_work) from [] (worker_thread+0x240/0x3a8) [] (worker_thread) from [] (kthread+0x100/0x118) [] (kthread) from [] (ret_from_fork+0x14/0x20) Signed-off-by: Doug Anderson --- FYI: making dw_mmc into a module and trying module removal was not tested. I'd appreciate any testing that folks can do there. This code should be the equivalent and makes the error case of probe match the removal case more closely now. drivers/mmc/host/dw_mmc.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 7f227e9..540ba3c 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -2577,10 +2577,6 @@ int dw_mci_probe(struct dw_mci *host) goto err_dmaunmap; } INIT_WORK(&host->card_work, dw_mci_work_routine_card); - ret = devm_request_irq(host->dev, host->irq, dw_mci_interrupt, - host->irq_flags, "dw-mci", host); - if (ret) - goto err_workqueue; if (host->pdata->num_slots) host->num_slots = host->pdata->num_slots; @@ -2619,11 +2615,21 @@ int dw_mci_probe(struct dw_mci *host) goto err_workqueue; } + ret = request_irq(host->irq, dw_mci_interrupt, host->irq_flags, + "dw-mci", host); + if (ret) + goto err_initted; + if (host->quirks & DW_MCI_QUIRK_IDMAC_DTO) dev_info(host->dev, "Internal DMAC interrupt fix enabled.\n"); return 0; +err_initted: + for (i = 0; i < host->num_slots; i++) + if (host->slot[i]) + dw_mci_cleanup_slot(host->slot[i], i); + err_workqueue: destroy_workqueue(host->card_workqueue); @@ -2649,8 +2655,7 @@ void dw_mci_remove(struct dw_mci *host) { int i; - mci_writel(host, RINTSTS, 0xFFFFFFFF); - mci_writel(host, INTMASK, 0); /* disable all mmc interrupt first */ + free_irq(host->irq, host); for (i = 0; i < host->num_slots; i++) { dev_dbg(host->dev, "remove slot %d\n", i);