[alsa-devel] [PATCH 2/8] add device specific command
Takashi Sakamoto
o-takashi at sakamocchi.jp
Thu Jun 6 19:33:40 CEST 2013
Clemens,
> Do you have the latest firmware in your AFPre8?
I use AFPre8 with firmware version 5.5 (0x5050000). I have never updated
it after I bought so it's factory setting.
> It can also be controlled by sending the commands directly (without
> the AV/C header) to address 0xecc000000000. This is one of the
> differences between FFADO and the Echo drivers,
I got packet dump and confirm there is no EFC over AVC. As you say, it
commands to 0xecc0 00000 0000 and receives response at 0xecc 8000 0000.
Then I implemented it and it looks to work fine. I also think it good to
use EFC without AVC.
> and might be related to the problems that FFADO has with the
> latest Fireworks firmware versions.
Later I'll update firmware in my device and search for this issue. But
it may be far future...
> That was part of my old driver, but most if this device-specific stuff
> is not needed for a simple kernel streaming driver.
OK. I use this transaction to confirm the device can respond but it's
needless. I'll remove it till posting improved patch.
Regards
Takashi Sakamoto
o-takashi at sakamocchi.jp
(Jun 3 2013 20:18), Clemens Ladisch wrote:
> o-takashi at sakamocchi.jp wrote:
>> Fireworks can be controlled by device specific commands over IEEE1394 TA's
>> AV/C Digital Interface Command Set.
>
> It can also be controlled by sending the commands directly (without the
> AV/C header) to address 0xecc000000000. This is one of the differences
> between FFADO and the Echo drivers, and might be related to the problems
> that FFADO has with the latest Fireworks firmware versions.
>
> Do you have the latest firmware in your AFPre8?
>
>> +struct avc_fields {
>> + unsigned short cts:4;
>> + unsigned short ctype:4;
>> ...
>
> The layout of bit fields are very unportable. And if you do *not*
> actually rely on the memory layout, you do not actually save space
> because the code to access the fields becomes more complex.
>
>> +efc_over_avc(struct snd_efw *efw, unsigned int category,
>
>> + /* AV/C fields */
>> + struct avc_fields avc_fields = {
>> + .cts = AVC_CTS,
>> + .ctype = AVC_CTYPE,
>> + .subunit_type = AVC_SUBUNIT_TYPE,
>> + .subunit_id = AVC_SUBUNIT_ID,
>> + .opcode = AVC_OPCODE,
>> + .company_id = AVC_COMPANY_ID
>> + };
>
> The compiler has to construct this on the stack. Use "static const".
>
>> + /* calcurate buffer size*/
>
> calculate
>
>> + if (param_count > response_quadlets)
>> + cmdbuf_bytes = 32 + param_count * 4;
>> + else
>> + cmdbuf_bytes = 32 + response_quadlets * 4;
>
> max()
>
>> +int snd_efw_command_identify(struct snd_efw *efw)
>> +{
>> + return efc_over_avc(efw, EFC_CAT_HWCTL,
>> + EFC_CMD_HWCTL_IDENTIFY,
>
> That was part of my old driver, but most if this device-specific stuff
> is not needed for a simple kernel streaming driver.
>
>
> Regards,
> Clemens
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