[alsa-devel] [PATCH] ALSA: hda - Defer probe when loading patch firmware

Thierry Reding thierry.reding at avionic-design.de
Thu Aug 9 08:45:23 CEST 2012

Recent changes to the firmware loading helpers cause drivers to stall
when firmware is loaded during the module_init() call. The snd-hda-intel
module requests firmware if the patch= parameter is used to load a patch
file. This patch works around the problem by deferring the probe in such
cases, which will cause the module to load successfully and the driver
binding to the device outside the module_init() call.

Signed-off-by: Thierry Reding <thierry.reding at avionic-design.de>
 sound/pci/hda/hda_intel.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index c8aced1..296616e 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -69,6 +69,7 @@ static int probe_only[SNDRV_CARDS];
 static bool single_cmd;
 static int enable_msi = -1;
+static bool deferred[SNDRV_CARDS];
 static char *patch[SNDRV_CARDS];
@@ -3156,6 +3157,16 @@ static int __devinit azx_probe(struct pci_dev *pci,
 	if (dev >= SNDRV_CARDS)
 		return -ENODEV;
+	if (patch[dev] && *patch[dev] && !deferred[dev]) {
+		snd_printk(KERN_ERR SFX "deferring probe for patch %s\n",
+			   patch[dev]);
+		deferred[dev] = true;
+		return -EPROBE_DEFER;
+	}
 	if (!enable[dev]) {
 		return -ENOENT;

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