[alsa-devel] [PATCH] ASoC: sgtl5000: Fix VAG_POWER enabling/disabling order
festevam at gmail.com
Tue May 28 16:10:35 CEST 2013
On Fri, May 24, 2013 at 12:34 AM, Marek Vasut <marex at denx.de> wrote:
> The VAG_POWER must be enabled after all other bits in CHIP_ANA_POWER
> and disabled before any other bit in CHIP_ANA_POWER. See the SGTL5000
> datasheet (Table 31, BIT 7, page 42-43). Failing to follow this order
> will result in ugly loud "POP" noise at the end of playback.
> To achieve such order, use the _PRE and _POST DAPM widgets to trigger
> the power_vag_event, where the event type check has to be fixed
> accordingly as well.
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Dong Aisheng <dong.aisheng at linaro.org>
> Cc: Eric Nelson <eric.nelson at boundarydevices.com>
> Cc: Fabio Estevam <fabio.estevam at freescale.com>
> Cc: Mark Brown <broonie at opensource.wolfsonmicro.com>
Thanks, tested on a mx51evk and it removes an annoying 'click' after
an audio track is played.
> - case SND_SOC_DAPM_POST_PMD:
> + case SND_SOC_DAPM_PRE_PMD:
> snd_soc_update_bits(w->codec, SGTL5000_CHIP_ANA_POWER,
> SGTL5000_VAG_POWERUP, 0);
> - msleep(400);
> + mdelay(400);
What is the reasoning for this change?
Tested-by: Fabio Estevam <fabio.estevam at freescale.com>
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