From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ulf Hansson Subject: Re: [PATCH] mmc: core: Fix deadlock when the CONFIG_MMC_UNSAFE_RESUME is not defined Date: Tue, 22 Nov 2011 16:43:46 +0100 Message-ID: <4ECBC332.9090407@stericsson.com> References: <1321961437-27130-1-git-send-email-sthumma@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from eu1sys200aog104.obsmtp.com ([207.126.144.117]:48642 "EHLO eu1sys200aog104.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755691Ab1KVPoD (ORCPT ); Tue, 22 Nov 2011 10:44:03 -0500 In-Reply-To: <1321961437-27130-1-git-send-email-sthumma@codeaurora.org> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Sujit Reddy Thumma Cc: "linux-mmc@vger.kernel.org" , "cjb@laptop.org" Sujit Reddy Thumma wrote: > mmc_suspend_host() tries to claim host during suspend > and release it only when the bus suspend operation is > compeleted. If CONFIG_MMC_UNSAFE_RESUME is defined and > the host is flagged as removable, mmc_suspend_host() > tries to remove the card. In this process, the file system > sync can get blocked trying to acquire host which is already > claimed by mmc_suspend_host() causing deadlock. > > Fix this deadlock by releasing host before ->remove() is called. > > Signed-off-by: Sujit Reddy Thumma > --- > drivers/mmc/core/core.c | 4 +++- > 1 files changed, 3 insertions(+), 1 deletions(-) > > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c > index 271efea..8adbadf 100644 > --- a/drivers/mmc/core/core.c > +++ b/drivers/mmc/core/core.c > @@ -2338,6 +2338,7 @@ int mmc_suspend_host(struct mmc_host *host) > * We simply "remove" the card in this case. > * It will be redetected on resume. > */ > + mmc_do_release_host(host); Instead of having an "else" below move mmc_do_release_host to be done before "if (err == -ENOSYS || !host->bus_ops->resume)" > if (host->bus_ops->remove) > host->bus_ops->remove(host); > mmc_claim_host(host); > @@ -2346,8 +2347,9 @@ int mmc_suspend_host(struct mmc_host *host) > mmc_release_host(host); > host->pm_flags = 0; > err = 0; > + } else { > + mmc_do_release_host(host); > } Remove else statement entirely. > - mmc_do_release_host(host); > } else { > err = -EBUSY; > } Otherwise it looks good to me! Thanks, for fixing this issue! Br Ulf Hansson