Return probe defer if requesting a dma channel without a dma controller
probed.

Signed-off-by: Ludovic Desroches <[email protected]>
---
 drivers/mmc/host/atmel-mci.c | 46 ++++++++++++++++++++++++--------------------
 1 file changed, 25 insertions(+), 21 deletions(-)

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 28546c3..d3c269e 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -2265,29 +2265,29 @@ static void atmci_cleanup_slot(struct atmel_mci_slot 
*slot,
        mmc_free_host(slot->mmc);
 }
 
-static bool atmci_configure_dma(struct atmel_mci *host)
+static int atmci_configure_dma(struct atmel_mci *host)
 {
-       if (host == NULL)
-               return false;
+       int ret = 0;
 
-       host->dma.chan = dma_request_slave_channel(&host->pdev->dev, "rxtx");
-       if (!host->dma.chan) {
-               dev_warn(&host->pdev->dev, "no DMA channel available\n");
-               return false;
-       } else {
-               dev_info(&host->pdev->dev,
-                                       "using %s for DMA transfers\n",
-                                       dma_chan_name(host->dma.chan));
-
-               host->dma_conf.src_addr = host->mapbase + ATMCI_RDR;
-               host->dma_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
-               host->dma_conf.src_maxburst = 1;
-               host->dma_conf.dst_addr = host->mapbase + ATMCI_TDR;
-               host->dma_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
-               host->dma_conf.dst_maxburst = 1;
-               host->dma_conf.device_fc = false;
-               return true;
+       host->dma.chan = dma_request_slave_channel_reason(&host->pdev->dev, 
"rxtx");
+       if (IS_ERR(host->dma.chan)) {
+               ret = PTR_ERR(host->dma.chan);
+               host->dma.chan = NULL;
+               return ret;
        }
+
+       dev_info(&host->pdev->dev, "using %s for DMA transfers\n",
+                dma_chan_name(host->dma.chan));
+
+       host->dma_conf.src_addr = host->mapbase + ATMCI_RDR;
+       host->dma_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+       host->dma_conf.src_maxburst = 1;
+       host->dma_conf.dst_addr = host->mapbase + ATMCI_TDR;
+       host->dma_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+       host->dma_conf.dst_maxburst = 1;
+       host->dma_conf.device_fc = false;
+
+       return ret;
 }
 
 /*
@@ -2403,7 +2403,10 @@ static int atmci_probe(struct platform_device *pdev)
 
        /* Get MCI capabilities and set operations according to it */
        atmci_get_cap(host);
-       if (atmci_configure_dma(host)) {
+       ret = atmci_configure_dma(host);
+       if (ret == -EPROBE_DEFER)
+               goto err_dma_probe_defer;
+       if (ret == 0) {
                host->prepare_data = &atmci_prepare_data_dma;
                host->submit_data = &atmci_submit_data_dma;
                host->stop_transfer = &atmci_stop_transfer_dma;
@@ -2476,6 +2479,7 @@ err_init_slot:
        del_timer_sync(&host->timer);
        if (host->dma.chan)
                dma_release_channel(host->dma.chan);
+err_dma_probe_defer:
        free_irq(irq, host);
        return ret;
 }
-- 
2.0.3

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