[alsa-devel] [PATCH] ALSA: ctl: allow TLV read operation for callback type of element in locked case

[Takashi Iwai]

On Mon, 23 Dec 2019 10:33:47 +0100,
Takashi Sakamoto wrote:
> 
> A design of ALSA control core allows applications to execute three
> operations for TLV feature; read, write and command. Furthermore, it
> allows driver developers to process the operations by two ways; allocated
> array or callback function. In the former, read operation is just allowed,
> thus developers uses the latter when device driver supports variety of
> models or the target model is expected to dynamically change information
> stored in TLV container.
> 
> The core also allows applications to lock any element so that the other
> applications can't perform write operation to the element for element
> value and TLV information. When the element is locked, write and command
> operation for TLV information are prohibited as well as element value.
> Any read operation should be allowed in the case.
> 
> At present, when an element has callback function for TLV information,
> TLV read operation returns EPERM if the element is locked. On the
> other hand, the read operation is success when an element has allocated
> array for TLV information. In both cases, read operation is success for
> element value expectedly.
> 
> This commit fixes the bug. This change can be backported to v4.14
> kernel or later.

The patch looks good but your sign-off is missing...


thanks,

Takashi