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Date: Tue, 10 Mar 2015 10:18:48 -0300
From: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
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To: linux-media@vger.kernel.org, mchehab@osg.samsung.com,
	hans.verkuil@cisco.com
Subject: em38xx locking question
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Mauro,

Function drivers/media/usb/em28xx/em28xx-video.c:get_next_buf
(copy pasted below for reference) does not take the list spinlock,
yet it modifies the list. Is that correct?

static inline struct em28xx_buffer *get_next_buf(struct em28xx *dev,
                                                 struct em28xx_dmaqueue *dma_q)
{
        struct em28xx_buffer *buf;

        if (list_empty(&dma_q->active)) {
                em28xx_isocdbg("No active queue to serve\n");
                return NULL;
        }
 
        /* Get the next buffer */
        buf = list_entry(dma_q->active.next, struct em28xx_buffer, list);
        /* Cleans up buffer - Useful for testing for frame/URB loss */
        list_del(&buf->list);
        buf->pos = 0; 
        buf->vb_buf = buf->mem;
 
        return buf;
}

Thanks!
-- 
Ezequiel Garcia, VanguardiaSur
www.vanguardiasur.com.ar