From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mauro Carvalho Chehab Date: Tue, 24 Aug 2010 12:52:36 +0000 Subject: Re: [PATCH] dvb: siano: free spinlock before schedule() Message-Id: <4C73C094.1000101@infradead.org> List-Id: References: <1280256161-7971-1-git-send-email-segooon@gmail.com> <4C4F5CA7.1030706@gmail.com> <20100808161022.GB5594@linux-m68k.org> In-Reply-To: <20100808161022.GB5594@linux-m68k.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Richard Zidlicky Cc: Jiri Slaby , Kulikov Vasiliy , kernel-janitors@vger.kernel.org, Douglas Schilling Landgraf , Jiri Kosina , Roel Kluin , Andrew Morton , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Em 08-08-2010 13:10, Richard Zidlicky escreveu: > On Wed, Jul 28, 2010 at 12:24:39AM +0200, Jiri Slaby wrote: > > sorry for seeing this so late, was flooded with email lately. > >> There is a better fix (which fixes the potential NULL dereference): >> http://lkml.org/lkml/2010/6/7/175 > >> Richard, could you address the comments there and resend? > > I am running this patch since many weeks (after fixing the compile error obviously). > Did not implement your beautification suggestion yet, was doing all kinds of experiments > with IR and had plenty of unrelated issues. This patch seems a way better than the previous patch. I've rebased it against the current tree (and fixed the identation). The only missing issue on it is the lack of your Signed-off-by. Richard, could you please send it to us? --- drivers/media/dvb/siano/smscoreapi.c | 31 +++++++++++++------------------ 1 file changed, 13 insertions(+), 18 deletions(-) --- patchwork.orig/drivers/media/dvb/siano/smscoreapi.c +++ patchwork/drivers/media/dvb/siano/smscoreapi.c @@ -1098,31 +1098,26 @@ EXPORT_SYMBOL_GPL(smscore_onresponse); * * @return pointer to descriptor on success, NULL on error. */ -struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev) + +struct smscore_buffer_t *get_entry(struct smscore_device_t *coredev) { struct smscore_buffer_t *cb = NULL; unsigned long flags; - DEFINE_WAIT(wait); - spin_lock_irqsave(&coredev->bufferslock, flags); + if (!list_empty(&coredev->buffers)) { + cb = (struct smscore_buffer_t *) coredev->buffers.next; + list_del(&cb->entry); + } + spin_unlock_irqrestore(&coredev->bufferslock, flags); + return cb; +} - /* This function must return a valid buffer, since the buffer list is - * finite, we check that there is an available buffer, if not, we wait - * until such buffer become available. - */ - - prepare_to_wait(&coredev->buffer_mng_waitq, &wait, TASK_INTERRUPTIBLE); - - if (list_empty(&coredev->buffers)) - schedule(); - - finish_wait(&coredev->buffer_mng_waitq, &wait); - - cb = (struct smscore_buffer_t *) coredev->buffers.next; - list_del(&cb->entry); +struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev) +{ + struct smscore_buffer_t *cb = NULL; - spin_unlock_irqrestore(&coredev->bufferslock, flags); + wait_event(coredev->buffer_mng_waitq, (cb = get_entry(coredev))); return cb; }