Hi Clemens,
Thanks for your comment.
On Apr 19 2018 17:54, Clemens Ladisch wrote:
Takashi Sakamoto wrote:
Recently I get Alesis Multimix 12 FireWire and work for ALSA dice driver to support it. This unit uses ASIC of 'WaveFront DICE II STD' and TCAT extended application protocol is not supported.
Unfortunately, the driver in v4.17-rc1 can't handle this unit, due to validation of address sections for global space. [...] (sound/firewire/dice/dice-interface.h) 175 #define GLOBAL_SAMPLE_RATE 0x05c ... 181 #define GLOBAL_VERSION 0x060 182 183 /* Some old firmware versions do not have the following global registers: */ ... 188 #define GLOBAL_CLOCK_CAPABILITIES 0x064
But this is not proper in my case because the maximum offset on global sub-address space is 0x05c in quadlet unit.
IIRC that comment was based on the documentation. Apparently, there was a misunderstanding of "size 0x60" vs. "up to the register at 0x60".
Aha. I'm OK.
From my curiosity, do you know which version of DICE firstly supports GLOBAL_VERSION register? Can you read it on the documentation?
In my opinion, GLOBAL_VERSION offset belongs to global address space for newer firmware version.
I agree; if this is how the hardware behaves, then this is what the driver should support.
The version register is checked only once (in get_subaddrs()) and does not actually affect the behaviour of the driver, so it would not hurt to simply omit that check on the old firmware. (And the "quadlets >= 90" check in dice_proc_read() needs to be adjusted.)
Hm. The check is applied to the other spaces such as rx/tx, so I'd like to leave it as is. With this patch[1], ALSA dice driver can handle the unit. In this weekend, I'll post it. Your reviewing is very helpful.
[1] https://github.com/takaswie/snd-firewire-improve/commit/1889e06b9593e16da281...
Thanks
Takashi Sakamoto