Am 19.02.2015 um 21:48 schrieb Javier Martinez Canillas:
On 02/19/2015 07:54 PM, Andreas Färber wrote:
Am 19.02.2015 um 19:40 schrieb Andreas Färber:
I updated max98088 and had it working on first boot, but on second boot it complained about the frequency:
[ 7.896834] max98088 7-0010: revision A [ 7.912776] snow-audio sound: HiFi <-> 3830000.i2s mapping ok [ 7.919367] max98088 7-0010: Invalid master clock frequency [ 7.919429] snow-audio sound: ASoC: Spring-I2S-MAX98089 late_probe() failed: -22 [ 7.920019] snow-audio sound: snd_soc_register_card failed (-22) [ 7.920109] snow-audio: probe of sound failed with error -22
I had the same error on Snow but even on the first boot and after doing some code archeology, I found the following commit [0] in a Samsung downstream tree that solves the issue.
The problem is that clk_round_rate(max98095->mclk, freq) returns 0 as the rounded rate if XCLOUT is not allowed to be re-parented on rate change.
Same on Spring:
diff --git a/sound/soc/codecs/max98088.c b/sound/soc/codecs/max98088.c index 1aa81321afba..46dc64675c26 100644 --- a/sound/soc/codecs/max98088.c +++ b/sound/soc/codecs/max98088.c @@ -1365,6 +1365,7 @@ static int max98088_dai_set_sysclk(struct snd_soc_dai *dai,
if (!IS_ERR(max98088->mclk)) { freq = clk_round_rate(max98088->mclk, freq); + dev_warn(codec->dev, "freq = %u\n", freq); clk_set_rate(max98088->mclk, freq); }
With Tushar's patch I see that clk_round_rate() returns 24000000 (24MHz) so the codec driver setups the correct PLL clock.
Ditto. With the clkout reparenting patch, clk_round_rate() returns 24MHz just like when double-beep-initialized. However when not double-beep-initialized, the driver initializes, but no audible output, so there must be another missing puzzle piece.
On a suspicion, the fourth boot I waited for the double-beep of the firmware (waiting for Ctrl+d/u), and then it did work.
So it seems the mclk is not always set up properly by the kernel, relying on firmware. Who's in charge of setting that clock up?
Right, it seems audio is only working due the firmware doing some previous setup. Probably it works on every boot if you have "sound init" as a part of the u-boot boot commands?
Indeed it does, 24 MHz without the reparenting patch, and sound working.
'sound init' code: https://github.com/afaerber/u-boot/blob/spring/drivers/sound/max98088.c
Regards, Andreas