linux-kernel - RE: [PATCH] ASoC: da7219: remove SRM lock check retry

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Message-ID: <CF33C36214C39B4496568E5578BE70C7403CAFAE@PGSMSX108.gar.corp.intel.com>
Date:   Tue, 3 Dec 2019 15:23:03 +0000
From:   "Lu, Brent" <brent.lu@...el.com>
To:     Adam Thomson <Adam.Thomson.Opensource@...semi.com>,
        "alsa-devel@...a-project.org" <alsa-devel@...a-project.org>
CC:     Support Opensource <Support.Opensource@...semi.com>,
        Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>,
        Jaroslav Kysela <perex@...ex.cz>,
        Takashi Iwai <tiwai@...e.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH] ASoC: da7219: remove SRM lock check retry


> 
> Yes, that's right. I have put in a request with our HW team to again clarify
> timings, but still awaiting feedback.
> 
> The driver already warns via the kernel logs when SRM lock fails as follows:
> 
> 	dev_warn(component->dev, "SRM failed to lock\n");
> 
> What else do you think is needed?
> 

Hi Adam,

Let's say that the SRM locks in the second loop. The 50ms delay was applied
but there is no kernel log message about it because the value of srm_lock is
already true when exiting the loop. If we can print every SRM lock fail before
msleep() call, it would be a helpful for people resolving timing issues like Cold
latency.

do {
	pll_status = snd_soc_component_read32(component, DA7219_PLL_SRM_STS);
	if (pll_status & DA7219_PLL_SRM_STS_SRM_LOCK) {
		break;
	} else {
		++i;
		dev_warn(component->dev, "SRM failed to lock, retry in 50ms\n");
		msleep(50);
	}
} while (i < DA7219_SRM_CHECK_RETRIES);


Regards,
Brent