Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936137AbXHGVBe (ORCPT ); Tue, 7 Aug 2007 17:01:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S935548AbXHGUuz (ORCPT ); Tue, 7 Aug 2007 16:50:55 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:56309 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935541AbXHGUuy (ORCPT ); Tue, 7 Aug 2007 16:50:54 -0400 Date: Tue, 7 Aug 2007 13:45:14 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Hans Verkuil , Mauro Carvalho Chehab Subject: [2.6.22.2 review 30/84] V4L: ivtv: Add locking to ensure stream setup is atomic Message-ID: <20070807204514.GE23028@kroah.com> References: <20070807204034.882009319@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="v4l-ivtv-add-locking-to-ensure-stream-setup-is-atomic.patch" In-Reply-To: <20070807204157.GA23028@kroah.com> User-Agent: Mutt/1.5.15 (2007-04-06) X-Bad-Reply: References and In-Reply-To but no 'Re:' in Subject. Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4548 Lines: 132 From: Hans Verkuil Starting an MPEG and VBI capture simultaneously caused errors in the VBI setup: this setup was done twice when it should be done only for the first stream that is opened. Added a mutex to prevent this from happening. (cherry picked from commit f885969196da6ae905162c0d1c5f0553de12cb40) Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Michael Krufky --- drivers/media/video/ivtv/ivtv-driver.c | 1 + drivers/media/video/ivtv/ivtv-driver.h | 1 + drivers/media/video/ivtv/ivtv-streams.c | 30 +++++++++++++++++++----------- 3 files changed, 21 insertions(+), 11 deletions(-) --- a/drivers/media/video/ivtv/ivtv-driver.c +++ b/drivers/media/video/ivtv/ivtv-driver.c @@ -622,6 +622,7 @@ static int __devinit ivtv_init_struct1(s itv->enc_mbox.max_mbox = 2; /* the encoder has 3 mailboxes (0-2) */ itv->dec_mbox.max_mbox = 1; /* the decoder has 2 mailboxes (0-1) */ + mutex_init(&itv->serialize_lock); mutex_init(&itv->i2c_bus_lock); mutex_init(&itv->udma.lock); --- a/drivers/media/video/ivtv/ivtv-driver.h +++ b/drivers/media/video/ivtv/ivtv-driver.h @@ -722,6 +722,7 @@ struct ivtv { int search_pack_header; spinlock_t dma_reg_lock; /* lock access to DMA engine registers */ + struct mutex serialize_lock; /* lock used to serialize starting streams */ /* User based DMA for OSD */ struct ivtv_user_dma udma; --- a/drivers/media/video/ivtv/ivtv-streams.c +++ b/drivers/media/video/ivtv/ivtv-streams.c @@ -446,6 +446,9 @@ int ivtv_start_v4l2_encode_stream(struct if (s->v4l2dev == NULL) return -EINVAL; + /* Big serialization lock to ensure no two streams are started + simultaneously: that can give all sorts of weird results. */ + mutex_lock(&itv->serialize_lock); IVTV_DEBUG_INFO("Start encoder stream %s\n", s->name); switch (s->type) { @@ -487,6 +490,7 @@ int ivtv_start_v4l2_encode_stream(struct 0, sizeof(itv->vbi.sliced_mpeg_size)); break; default: + mutex_unlock(&itv->serialize_lock); return -EINVAL; } s->subtype = subtype; @@ -568,6 +572,7 @@ int ivtv_start_v4l2_encode_stream(struct if (ivtv_vapi(itv, CX2341X_ENC_START_CAPTURE, 2, captype, subtype)) { IVTV_DEBUG_WARN( "Error starting capture!\n"); + mutex_unlock(&itv->serialize_lock); return -EINVAL; } @@ -583,6 +588,7 @@ int ivtv_start_v4l2_encode_stream(struct /* you're live! sit back and await interrupts :) */ atomic_inc(&itv->capturing); + mutex_unlock(&itv->serialize_lock); return 0; } @@ -762,17 +768,6 @@ int ivtv_stop_v4l2_encode_stream(struct /* when: 0 = end of GOP 1 = NOW!, type: 0 = mpeg, subtype: 3 = video+audio */ ivtv_vapi(itv, CX2341X_ENC_STOP_CAPTURE, 3, stopmode, cap_type, s->subtype); - /* only run these if we're shutting down the last cap */ - if (atomic_read(&itv->capturing) - 1 == 0) { - /* event notification (off) */ - if (test_and_clear_bit(IVTV_F_I_DIG_RST, &itv->i_flags)) { - /* type: 0 = refresh */ - /* on/off: 0 = off, intr: 0x10000000, mbox_id: -1: none */ - ivtv_vapi(itv, CX2341X_ENC_SET_EVENT_NOTIFICATION, 4, 0, 0, IVTV_IRQ_ENC_VIM_RST, -1); - ivtv_set_irq_mask(itv, IVTV_IRQ_ENC_VIM_RST); - } - } - then = jiffies; if (!test_bit(IVTV_F_S_PASSTHROUGH, &s->s_flags)) { @@ -840,17 +835,30 @@ int ivtv_stop_v4l2_encode_stream(struct /* Clear capture and no-read bits */ clear_bit(IVTV_F_S_STREAMING, &s->s_flags); + /* ensure these global cleanup actions are done only once */ + mutex_lock(&itv->serialize_lock); + if (s->type == IVTV_ENC_STREAM_TYPE_VBI) ivtv_set_irq_mask(itv, IVTV_IRQ_ENC_VBI_CAP); if (atomic_read(&itv->capturing) > 0) { + mutex_unlock(&itv->serialize_lock); return 0; } /* Set the following Interrupt mask bits for capture */ ivtv_set_irq_mask(itv, IVTV_IRQ_MASK_CAPTURE); + /* event notification (off) */ + if (test_and_clear_bit(IVTV_F_I_DIG_RST, &itv->i_flags)) { + /* type: 0 = refresh */ + /* on/off: 0 = off, intr: 0x10000000, mbox_id: -1: none */ + ivtv_vapi(itv, CX2341X_ENC_SET_EVENT_NOTIFICATION, 4, 0, 0, IVTV_IRQ_ENC_VIM_RST, -1); + ivtv_set_irq_mask(itv, IVTV_IRQ_ENC_VIM_RST); + } + wake_up(&s->waitq); + mutex_unlock(&itv->serialize_lock); return 0; } -- - 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/