Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755886AbYGYIpg (ORCPT ); Fri, 25 Jul 2008 04:45:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752678AbYGYIp0 (ORCPT ); Fri, 25 Jul 2008 04:45:26 -0400 Received: from smtp.wellnetcz.com ([212.24.148.102]:54295 "EHLO smtp.wellnetcz.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752309AbYGYIpX (ORCPT ); Fri, 25 Jul 2008 04:45:23 -0400 From: Jiri Slaby To: airlied@linux.ie Cc: Andrew Morton , dri-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Jiri Slaby Subject: [PATCH 1/1 repost #1] DRM: don't enable irqs in locking Date: Fri, 25 Jul 2008 10:42:49 +0200 Message-Id: <1216975369-6749-1-git-send-email-jirislaby@gmail.com> X-Mailer: git-send-email 1.5.6.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3166 Lines: 87 drm_lock_take(); and drm_lock_free(); are called from drm_locked_tasklet_func(); which disables interrupts when grabbing its spinlock. Don't allow these locking functions to re-enable interrupts when the tasklet expects them disabled. I.e. use spin_lock_irqsave instead of spin_lock_bh (with their unlock opposites). We will get such a warnings otherwise: ------------[ cut here ]------------ WARNING: at kernel/softirq.c:136 local_bh_enable_ip+0x8b/0xb0() Modules linked in: arc4 ecb crypto_blkcipher cryptomgr crypto_algapi ath5k usbhid mac80211 ohci1394 hid led_class floppy cfg80211 ff_memless ieee1394 rtc_cmos evdev [last unloaded: freq_table] Pid: 0, comm: swapper Not tainted 2.6.26-rc8-mm1_64 #427 Call Trace: [] warn_on_slowpath+0x5f/0x90 [...] [] local_bh_enable_ip+0x8b/0xb0 [] _spin_unlock_bh+0xf/0x20 [] drm_lock_take+0x81/0xe0 [] drm_locked_tasklet_func+0x4b/0xb0 [] tasklet_hi_action+0x69/0xf0 [] __do_softirq+0x84/0xf0 [stack snipped] Signed-off-by: Jiri Slaby Cc: David Airlie --- drivers/gpu/drm/drm_lock.c | 12 +++++++----- 1 files changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/drm_lock.c b/drivers/gpu/drm/drm_lock.c index 0998723..79943e4 100644 --- a/drivers/gpu/drm/drm_lock.c +++ b/drivers/gpu/drm/drm_lock.c @@ -196,10 +196,11 @@ int drm_unlock(struct drm_device *dev, void *data, struct drm_file *file_priv) int drm_lock_take(struct drm_lock_data *lock_data, unsigned int context) { + unsigned long flags; unsigned int old, new, prev; volatile unsigned int *lock = &lock_data->hw_lock->lock; - spin_lock_bh(&lock_data->spinlock); + spin_lock_irqsave(&lock_data->spinlock, flags); do { old = *lock; if (old & _DRM_LOCK_HELD) @@ -211,7 +212,7 @@ int drm_lock_take(struct drm_lock_data *lock_data, } prev = cmpxchg(lock, old, new); } while (prev != old); - spin_unlock_bh(&lock_data->spinlock); + spin_unlock_irqrestore(&lock_data->spinlock, flags); if (_DRM_LOCKING_CONTEXT(old) == context) { if (old & _DRM_LOCK_HELD) { @@ -270,17 +271,18 @@ static int drm_lock_transfer(struct drm_lock_data *lock_data, */ int drm_lock_free(struct drm_lock_data *lock_data, unsigned int context) { + unsigned long flags; unsigned int old, new, prev; volatile unsigned int *lock = &lock_data->hw_lock->lock; - spin_lock_bh(&lock_data->spinlock); + spin_lock_irqsave(&lock_data->spinlock, flags); if (lock_data->kernel_waiters != 0) { drm_lock_transfer(lock_data, 0); lock_data->idle_has_lock = 1; - spin_unlock_bh(&lock_data->spinlock); + spin_unlock_irqrestore(&lock_data->spinlock, flags); return 1; } - spin_unlock_bh(&lock_data->spinlock); + spin_unlock_irqrestore(&lock_data->spinlock, flags); do { old = *lock; -- 1.5.6.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/