From: Guennadi Liakhovetski Date: Tue, 31 Mar 2009 06:44:22 +0000 (-0300) Subject: V4L/DVB (11323): pxa-camera: simplify the .buf_queue path by merging two loops X-Git-Tag: accepted/tizen/common/20141203.182822~16546^2~114 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ae7410e712b33d32337df80f71f702d12a8ebb81;p=platform%2Fkernel%2Flinux-arm64.git V4L/DVB (11323): pxa-camera: simplify the .buf_queue path by merging two loops pxa_dma_update_sg_tail() is called only once, runs exactly the same loop as the caller and has to recalculate the last element in an sg-list, that the caller has already calculated. Eliminate redundancy by merging the two loops and re-using the calculated pointer. This also saves a bit of performance which is always good during video-capture. Signed-off-by: Guennadi Liakhovetski Acked-by: Robert Jarzmik Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/video/pxa_camera.c b/drivers/media/video/pxa_camera.c index cfa113c..c639845 100644 --- a/drivers/media/video/pxa_camera.c +++ b/drivers/media/video/pxa_camera.c @@ -566,15 +566,6 @@ static void pxa_dma_stop_channels(struct pxa_camera_dev *pcdev) } } -static void pxa_dma_update_sg_tail(struct pxa_camera_dev *pcdev, - struct pxa_buffer *buf) -{ - int i; - - for (i = 0; i < pcdev->channels; i++) - pcdev->sg_tail[i] = buf->dmas[i].sg_cpu + buf->dmas[i].sglen; -} - static void pxa_dma_add_tail_buf(struct pxa_camera_dev *pcdev, struct pxa_buffer *buf) { @@ -585,12 +576,13 @@ static void pxa_dma_add_tail_buf(struct pxa_camera_dev *pcdev, buf_last_desc = buf->dmas[i].sg_cpu + buf->dmas[i].sglen; buf_last_desc->ddadr = DDADR_STOP; - if (!pcdev->sg_tail[i]) - continue; - pcdev->sg_tail[i]->ddadr = buf->dmas[i].sg_dma; - } + if (pcdev->sg_tail[i]) + /* Link the new buffer to the old tail */ + pcdev->sg_tail[i]->ddadr = buf->dmas[i].sg_dma; - pxa_dma_update_sg_tail(pcdev, buf); + /* Update the channel tail */ + pcdev->sg_tail[i] = buf_last_desc; + } } /**