[PATCH] ALSA: hda: Abort capability probe on invalid capability

[PATCH] ALSA: hda: Abort capability probe on invalid capability

[Ughreja, Rakesh A]

From: Rakesh Ughreja <rakesh.a.ughreja@intel.com>

When an invalid capability is discovered, stop traversing
the capability link list further.

print the invalid capability error and set it to zero

Signed-off-by: Rakesh Ughreja <rakesh.a.ughreja@intel.com>
---
 sound/hda/hdac_controller.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sound/hda/hdac_controller.c b/sound/hda/hdac_controller.c
index 978dc18..8f7d0d9 100644
--- a/sound/hda/hdac_controller.c
+++ b/sound/hda/hdac_controller.c
@@ -314,7 +314,8 @@ int snd_hdac_bus_parse_capabilities(struct hdac_bus *bus)
 			break;
 
 		default:
-			dev_dbg(bus->dev, "Unknown capability %d\n", cur_cap);
+			dev_err(bus->dev, "Unknown capability %d\n", cur_cap);
+			cur_cap = 0;
 			break;
 		}
 
-- 
2.7.4

[PATCH] ALSA: hda: Abort capability probe on invalid capability

[Ughreja, Rakesh A]

From: Rakesh Ughreja <rakesh.a.ughreja@intel.com>

When an invalid capability is discovered, stop traversing
the capability link list further.

Signed-off-by: Rakesh Ughreja <rakesh.a.ughreja@intel.com>
---
 sound/hda/hdac_controller.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sound/hda/hdac_controller.c b/sound/hda/hdac_controller.c
index 978dc18..4fa0cc0 100644
--- a/sound/hda/hdac_controller.c
+++ b/sound/hda/hdac_controller.c
@@ -314,7 +314,8 @@ int snd_hdac_bus_parse_capabilities(struct hdac_bus *bus)
 			break;
 
 		default:
-			dev_dbg(bus->dev, "Unknown capability %d\n", cur_cap);
+			cur_cap = 0;
+			dev_err(bus->dev, "Unknown capability %d\n", cur_cap);
 			break;
 		}
 
-- 
2.7.4

Re: [PATCH] ALSA: hda: Abort capability probe on invalid capability

[Takashi Iwai]

On Wed, 18 Oct 2017 12:29:14 +0200,
Ughreja, Rakesh A wrote:
> 
> 
> 
> >-----Original Message-----
> >From: Takashi Iwai [mailto:tiwai@suse.de]
> >Sent: Wednesday, October 18, 2017 3:50 PM
> >To: Ughreja, Rakesh A <rakesh.a.ughreja@intel.com>
> >Cc: alsa-devel@alsa-project.org; Koul, Vinod <vinod.koul@intel.com>
> >Subject: Re: [PATCH] ALSA: hda: Abort capability probe on invalid capability
> >
> >On Wed, 18 Oct 2017 19:59:36 +0200,
> >Ughreja, Rakesh A wrote:
> >>
> >> From: Rakesh Ughreja <rakesh.a.ughreja@intel.com>
> >>
> >> When an invalid capability is discovered, stop traversing
> >> the capability link list further.
> >
> >Could you give more background, especially *why* we change that?
> >It's almost clear what the patch does by looking at the change, but
> >it's not clear why it is needed.
> 
> Is the following description in patch okay for you ?
> 
> Due to bugs in BIOS it's possible that the HDA capability link list is 
> not constructed properly. This may lead to driver going into unknown
> state. So whenever driver discovers unknown HDA capability, 
> log it as error and stop traversing the link list further.

Yes, looks good.


thanks,

Takashi

Re: [PATCH] ALSA: hda: Abort capability probe on invalid capability

[Ughreja, Rakesh A]

>-----Original Message-----
>From: Takashi Iwai [mailto:tiwai@suse.de]
>Sent: Wednesday, October 18, 2017 3:50 PM
>To: Ughreja, Rakesh A <rakesh.a.ughreja@intel.com>
>Cc: alsa-devel@alsa-project.org; Koul, Vinod <vinod.koul@intel.com>
>Subject: Re: [PATCH] ALSA: hda: Abort capability probe on invalid capability
>
>On Wed, 18 Oct 2017 19:59:36 +0200,
>Ughreja, Rakesh A wrote:
>>
>> From: Rakesh Ughreja <rakesh.a.ughreja@intel.com>
>>
>> When an invalid capability is discovered, stop traversing
>> the capability link list further.
>
>Could you give more background, especially *why* we change that?
>It's almost clear what the patch does by looking at the change, but
>it's not clear why it is needed.

Is the following description in patch okay for you ?

Due to bugs in BIOS it's possible that the HDA capability link list is 
not constructed properly. This may lead to driver going into unknown
state. So whenever driver discovers unknown HDA capability, 
log it as error and stop traversing the link list further.

Regards,
Rakesh
 

Re: [PATCH] ALSA: hda: Abort capability probe on invalid capability

[Takashi Iwai]

On Wed, 18 Oct 2017 19:59:36 +0200,
Ughreja, Rakesh A wrote:
> 
> From: Rakesh Ughreja <rakesh.a.ughreja@intel.com>
> 
> When an invalid capability is discovered, stop traversing
> the capability link list further.

Could you give more background, especially *why* we change that?
It's almost clear what the patch does by looking at the change, but
it's not clear why it is needed.


thanks,

Takashi


> Signed-off-by: Rakesh Ughreja <rakesh.a.ughreja@intel.com>
> ---
>  sound/hda/hdac_controller.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/sound/hda/hdac_controller.c b/sound/hda/hdac_controller.c
> index 978dc18..4fa0cc0 100644
> --- a/sound/hda/hdac_controller.c
> +++ b/sound/hda/hdac_controller.c
> @@ -314,7 +314,8 @@ int snd_hdac_bus_parse_capabilities(struct hdac_bus *bus)
>  			break;
>  
>  		default:
> -			dev_dbg(bus->dev, "Unknown capability %d\n", cur_cap);
> +			cur_cap = 0;
> +			dev_err(bus->dev, "Unknown capability %d\n", cur_cap);
>  			break;
>  		}
>  
> -- 
> 2.7.4
>