mmc: dw_mmc: allow biu and ciu clocks to defer

Fix a race condition if the clock provider comes up after mmc is probed,
this causes mmc to fail without retrying.
When given the DEFER error from the clk source, pass it on up the chain.

Fixes: f90a061 ("mmc: dw_mmc: lookup for optional biu and ciu clocks")
Signed-off-by: Ben Whitten <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Ulf Hansson <[email protected]>

Author: BWhitten

drivers/mmc/host/dw_mmc.c

@@ -3299,6 +3299,10 @@ int dw_mci_probe(struct dw_mci *host)
 	host->biu_clk = devm_clk_get(host->dev, "biu");
 	if (IS_ERR(host->biu_clk)) {
 		dev_dbg(host->dev, "biu clock not available\n");
+		ret = PTR_ERR(host->biu_clk);
+		if (ret == -EPROBE_DEFER)
+			return ret;
+
 	} else {
 		ret = clk_prepare_enable(host->biu_clk);
 		if (ret) {
@@ -3310,6 +3314,10 @@ int dw_mci_probe(struct dw_mci *host)
 	host->ciu_clk = devm_clk_get(host->dev, "ciu");
 	if (IS_ERR(host->ciu_clk)) {
 		dev_dbg(host->dev, "ciu clock not available\n");
+		ret = PTR_ERR(host->ciu_clk);
+		if (ret == -EPROBE_DEFER)
+			goto err_clk_biu;
+
 		host->bus_hz = host->pdata->bus_hz;
 	} else {
 		ret = clk_prepare_enable(host->ciu_clk);