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From: Andreas Mohr <andi@lisas.de>
To: linux-kernel@vger.kernel.org
Cc: Greg KH <greg@kroah.com>, Julia Lawall <julia@diku.dk>
Subject: mcs7830 usb net: "scheduling while atomic" danger?
Date: Mon, 18 Jan 2010 19:49:42 +0100	[thread overview]
Message-ID: <20100118184942.GA10171@rhlx01.hs-esslingen.de> (raw)

Hi,

drivers/net/usb/mcs7830.c does several:

        mutex_lock(&dev->phy_mutex);
        /* write the MII command */
        ret = mcs7830_set_reg(dev, HIF_REG_PHY_CMD1, 2, cmd);
        if (ret < 0)
                goto out;

        /* wait for the data to become valid, should be within < 1ms */
        for (i = 0; i < 10; i++) {
                ret = mcs7830_get_reg(dev, HIF_REG_PHY_CMD1, 2, cmd);
                if ((ret < 0) || (cmd[1] &
HIF_REG_PHY_CMD2_READY_FLAG_BIT))
                        break;
                ret = -EIO;
                msleep(1);
        }


Forgive me, but doesn't that mutex_lock()/msleep() (ab)use mean
risking a "scheduling while atomic"?
(such as discussed in e.g.
http://search.luky.org/linux-kernel.2004/msg92817.html )


And, if that is the case, shouldn't all such cases simply be killed for
good via a capable semantic patch?

Thanks,

Andreas Mohr

             reply	other threads:[~2010-01-18 18:49 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-18 18:49 Andreas Mohr [this message]
2010-01-18 20:25 ` Julia Lawall
2010-01-18 20:47 ` Thomas Gleixner
2010-01-18 21:10 ` Julia Lawall
2010-01-18 21:23   ` Arnd Bergmann
2010-01-18 21:35     ` Julia Lawall
2010-01-18 22:25       ` Arnd Bergmann
2010-01-19  8:31         ` [PATCH] ehci: phy low power mode bug fixing alek du
2010-01-19  2:53     ` mcs7830 usb net: "scheduling while atomic" danger? Du, Alek
2010-01-19  6:25       ` Julia Lawall
2010-01-18 21:24   ` Thomas Gleixner
2010-01-18 21:32     ` Julia Lawall
2010-01-18 21:38       ` Thomas Gleixner

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