[alsa-devel] Alsa 1.0.15rc2 and oops with Dell M1210

[Takashi Iwai]

At Wed, 3 Oct 2007 16:58:35 -0300,
Herton Ronaldo Krzesinski wrote:
> 
> Em Saturday 29 September 2007 18:53:29 Herton Ronaldo Krzesinski escreveu:
> > On Saturday 29 September 2007 06:07:17 zhejiang wrote:
> > > Seems that the spec->input_mux contains no item at all.
> > > So system maybe crash in the snd_hda_input_mux_info() when try to copy
> > > the items[].label,which is null pointer.
> > >
> > > May you replace the function  stac92xx_mux_enum_info() in
> > > alsa-driver-1.0.15rc2/alsa-kernel/pci/hda/patch_sigmatel.c ?
> > >
> > > static int stac92xx_mux_enum_info(struct snd_kcontrol *kcontrol, struct
> > > snd_ctl_elem_info *uinfo)
> > > {
> > > 	struct hda_codec *codec = snd_kcontrol_chip(kcontrol);
> > > 	struct sigmatel_spec *spec = codec->spec;
> > > 	printk("spec->input_mux->num_items is %d
> > > \n",spec->input_mux->num_items);
> > > 	if(!spec->input_mux->num_items)
> > > 		return 0;
> > > 	return snd_hda_input_mux_info(spec->input_mux, uinfo);
> > > }
> > >
> > > Does it still crash?
> > > What's the number of num_items?
> 
> I received feedback from the reporter:
> spec->input_mux->num_items is 0
> 
> Also sound works fine, no more crashes.

OK, then could you check whether the patch below fixes the problem?
Such a check should be done in the common routine.


Thanks,

Takashi

diff -r a4cf3aa3dc5b pci/hda/hda_codec.c
--- a/pci/hda/hda_codec.c	Tue Oct 09 10:34:06 2007 +0200
+++ b/pci/hda/hda_codec.c	Tue Oct 09 11:53:39 2007 +0200
@@ -2341,6 +2341,8 @@ int snd_hda_input_mux_info(const struct 
 	uinfo->type = SNDRV_CTL_ELEM_TYPE_ENUMERATED;
 	uinfo->count = 1;
 	uinfo->value.enumerated.items = imux->num_items;
+	if (!imux->num_items)
+		return 0;
 	index = uinfo->value.enumerated.item;
 	if (index >= imux->num_items)
 		index = imux->num_items - 1;
@@ -2356,6 +2358,8 @@ int snd_hda_input_mux_put(struct hda_cod
 {
 	unsigned int idx;
 
+	if (!imux->num_items)
+		return 0;
 	idx = ucontrol->value.enumerated.item[0];
 	if (idx >= imux->num_items)
 		idx = imux->num_items - 1;