pxa2xx-ac97: switch AC unit to correct state before probing

If AC97 unit is in partially enabled state, early request_irq can trigger
IRQ storm or even full hang up. Workaround this by forcibly switching ACLINK off
at the start of the probe.

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 16 insertions, 9 deletions

diff --git a/sound/arm/pxa2xx-ac97-lib.c b/sound/arm/pxa2xx-ac97-lib.c
index ef6539eea579..35afd0c33be5 100644
--- a/sound/arm/pxa2xx-ac97-lib.c
+++ b/sound/arm/pxa2xx-ac97-lib.c
@@ -321,10 +321,6 @@ int __devinit pxa2xx_ac97_hw_probe(struct platform_device *dev)
 {
         int ret;
 
-        ret = request_irq(IRQ_AC97, pxa2xx_ac97_irq, 0, "AC97", NULL);
-        if (ret < 0)
-                goto err;
-
         if (cpu_is_pxa25x() || cpu_is_pxa27x()) {
                 pxa_gpio_mode(GPIO31_SYNC_AC97_MD);
                 pxa_gpio_mode(GPIO30_SDATA_OUT_AC97_MD);
@@ -339,7 +335,7 @@ int __devinit pxa2xx_ac97_hw_probe(struct platform_device *dev)
                 if (IS_ERR(ac97conf_clk)) {
                         ret = PTR_ERR(ac97conf_clk);
                         ac97conf_clk = NULL;
-                        goto err_irq;
+                        goto err_conf;
                 }
         }
 
@@ -347,19 +343,30 @@ int __devinit pxa2xx_ac97_hw_probe(struct platform_device *dev)
         if (IS_ERR(ac97_clk)) {
                 ret = PTR_ERR(ac97_clk);
                 ac97_clk = NULL;
-                goto err_irq;
+                goto err_clk;
         }
 
-        return clk_enable(ac97_clk);
+        ret = clk_enable(ac97_clk);
+        if (ret)
+                goto err_clk2;
+
+        ret = request_irq(IRQ_AC97, pxa2xx_ac97_irq, IRQF_DISABLED, "AC97", NULL);
+        if (ret < 0)
+                goto err_irq;
+
+        return 0;
 
 err_irq:
         GCR |= GCR_ACLINK_OFF;
+err_clk2:
+        clk_put(ac97_clk);
+        ac97_clk = NULL;
+err_clk:
         if (ac97conf_clk) {
                 clk_put(ac97conf_clk);
                 ac97conf_clk = NULL;
         }
-        free_irq(IRQ_AC97, NULL);
-err:
+err_conf:
         return ret;
 }
 EXPORT_SYMBOL_GPL(pxa2xx_ac97_hw_probe);