[alsa-devel] [PATCH 12/13] [media] omap3isp: Support for deferred probing when requesting DMA channel

[Peter Ujfalusi]

Switch to use ma_request_slave_channel_compat_reason() to request the DMA
channel. Only fall back to pio mode if the error code returned is not
-EPROBE_DEFER, otherwise return from the probe with the -EPROBE_DEFER.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
CC: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
CC: Mauro Carvalho Chehab <mchehab at osg.samsung.com>
---
 drivers/media/platform/omap3isp/isphist.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/omap3isp/isphist.c b/drivers/media/platform/omap3isp/isphist.c
index 7138b043a4aa..e690ca13af0e 100644
--- a/drivers/media/platform/omap3isp/isphist.c
+++ b/drivers/media/platform/omap3isp/isphist.c
@@ -499,14 +499,20 @@ int omap3isp_hist_init(struct isp_device *isp)
 		if (res)
 			sig = res->start;
 
-		hist->dma_ch = dma_request_slave_channel_compat(mask,
+		hist->dma_ch = dma_request_slave_channel_compat_reason(mask,
 				omap_dma_filter_fn, &sig, isp->dev, "hist");
-		if (!hist->dma_ch)
+		if (IS_ERR(hist->dma_ch)) {
+			ret = PTR_ERR(hist->dma_ch);
+			if (ret == -EPROBE_DEFER)
+				return ret;
+
+			hist->dma_ch = NULL;
 			dev_warn(isp->dev,
 				 "hist: DMA channel request failed, using PIO\n");
-		else
+		} else {
 			dev_dbg(isp->dev, "hist: using DMA channel %s\n",
 				dma_chan_name(hist->dma_ch));
+		}
 	}
 
 	hist->ops = &hist_ops;
-- 
2.3.5