From: Yakir <ykk@rock-chips.com>
To: Russell King <rmk+kernel@arm.linux.org.uk>,
alsa-devel@alsa-project.org, dri-devel@lists.freedesktop.org,
linux-arm-kernel@lists.infradead.org
Cc: Fabio Estevam <fabio.estevam@freescale.com>,
David Airlie <airlied@linux.ie>, Takashi Iwai <tiwai@suse.de>,
Mark Brown <broonie@kernel.org>,
Philipp Zabel <p.zabel@pengutronix.de>
Subject: Re: [PATCH 08/13] drm: bridge/dw_hdmi: introduce interfaces to enable and disable audio
Date: Fri, 22 May 2015 23:28:58 +0800 [thread overview]
Message-ID: <555F4B3A.3070907@rock-chips.com> (raw)
In-Reply-To: <E1Yr1xo-0006l0-8E@rmk-PC.arm.linux.org.uk>
Hi Russell,
在 2015/5/9 18:26, Russell King 写道:
> iMX6 devices suffer from an errata (ERR005174) where the audio FIFO can
> be emptied while it is partially full, resulting in misalignment of the
> audio samples.
>
> To prevent this, the errata workaround recommends writing N as zero
> until the audio FIFO has been loaded by DMA. Writing N=0 prevents the
> HDMI bridge from reading from the audio FIFO, effectively disabling
> audio.
>
> This means we need to provide the audio driver with a pair of functions
> to enable/disable audio. These are dw_hdmi_audio_enable() and
> dw_hdmi_audio_disable().
>
> A spinlock is introduced to ensure that setting the CTS/N values can't
> race, ensuring that the audio driver calling the enable/disable
> functions (which are called in an atomic context) can't race with a
> modeset.
>
> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Test on RK3288 platform, it works wells. Previously I use to switch off
the i2s audio clock, for now seems it is not necessary.
Test-by: Yakir Yang <ykk@rock-chips.com>
Thanks,
Yakir Yang
> ---
> drivers/gpu/drm/bridge/dw_hdmi.c | 34 +++++++++++++++++++++++++++++++++-
> include/drm/bridge/dw_hdmi.h | 2 ++
> 2 files changed, 35 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/bridge/dw_hdmi.c b/drivers/gpu/drm/bridge/dw_hdmi.c
> index 0369fab5c695..adda3a988f36 100644
> --- a/drivers/gpu/drm/bridge/dw_hdmi.c
> +++ b/drivers/gpu/drm/bridge/dw_hdmi.c
> @@ -18,6 +18,7 @@
> #include <linux/hdmi.h>
> #include <linux/mutex.h>
> #include <linux/of_device.h>
> +#include <linux/spinlock.h>
>
> #include <drm/drm_of.h>
> #include <drm/drmP.h>
> @@ -124,8 +125,12 @@ struct dw_hdmi {
> struct i2c_adapter *ddc;
> void __iomem *regs;
>
> + spinlock_t audio_lock;
> struct mutex audio_mutex;
> unsigned int sample_rate;
> + unsigned int audio_cts;
> + unsigned int audio_n;
> + bool audio_enable;
> int ratio;
>
> void (*write)(struct dw_hdmi *hdmi, u8 val, int offset);
> @@ -347,7 +352,11 @@ static void hdmi_set_clk_regenerator(struct dw_hdmi *hdmi,
> dev_dbg(hdmi->dev, "%s: samplerate=%ukHz ratio=%d pixelclk=%luMHz N=%d cts=%d\n",
> __func__, sample_rate, ratio, pixel_clk, n, cts);
>
> - hdmi_set_cts_n(hdmi, cts, n);
> + spin_lock_irq(&hdmi->audio_lock);
> + hdmi->audio_n = n;
> + hdmi->audio_cts = cts;
> + hdmi_set_cts_n(hdmi, cts, hdmi->audio_enable ? n : 0);
> + spin_unlock_irq(&hdmi->audio_lock);
> }
>
> static void hdmi_init_clk_regenerator(struct dw_hdmi *hdmi)
> @@ -376,6 +385,28 @@ void dw_hdmi_set_sample_rate(struct dw_hdmi *hdmi, unsigned int rate)
> }
> EXPORT_SYMBOL_GPL(dw_hdmi_set_sample_rate);
>
> +void dw_hdmi_audio_enable(struct dw_hdmi *hdmi)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&hdmi->audio_lock, flags);
> + hdmi->audio_enable = true;
> + hdmi_set_cts_n(hdmi, hdmi->audio_cts, hdmi->audio_n);
> + spin_unlock_irqrestore(&hdmi->audio_lock, flags);
> +}
> +EXPORT_SYMBOL_GPL(dw_hdmi_audio_enable);
> +
> +void dw_hdmi_audio_disable(struct dw_hdmi *hdmi)
> +{
> + unsigned long flags;
> +
> + spin_lock_irqsave(&hdmi->audio_lock, flags);
> + hdmi->audio_enable = false;
> + hdmi_set_cts_n(hdmi, hdmi->audio_cts, 0);
> + spin_unlock_irqrestore(&hdmi->audio_lock, flags);
> +}
> +EXPORT_SYMBOL_GPL(dw_hdmi_audio_disable);
> +
> /*
> * this submodule is responsible for the video data synchronization.
> * for example, for RGB 4:4:4 input, the data map is defined as
> @@ -1578,6 +1609,7 @@ int dw_hdmi_bind(struct device *dev, struct device *master,
> hdmi->encoder = encoder;
>
> mutex_init(&hdmi->audio_mutex);
> + spin_lock_init(&hdmi->audio_lock);
>
> of_property_read_u32(np, "reg-io-width", &val);
>
> diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
> index 763af51e1d60..bae79f3c4d28 100644
> --- a/include/drm/bridge/dw_hdmi.h
> +++ b/include/drm/bridge/dw_hdmi.h
> @@ -63,5 +63,7 @@ int dw_hdmi_bind(struct device *dev, struct device *master,
> const struct dw_hdmi_plat_data *plat_data);
>
> void dw_hdmi_set_sample_rate(struct dw_hdmi *hdmi, unsigned int rate);
> +void dw_hdmi_audio_enable(struct dw_hdmi *hdmi);
> +void dw_hdmi_audio_disable(struct dw_hdmi *hdmi);
>
> #endif /* __IMX_HDMI_H__ */
_______________________________________________
Alsa-devel mailing list
Alsa-devel@alsa-project.org
http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
next prev parent reply other threads:[~2015-05-22 15:29 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-02 9:20 [RFC v2 0/13] dw_hdmi cleanups, audio preparation, helpers and ahb audio support Russell King - ARM Linux
2015-04-02 9:21 ` [PATCH RFC v2 01/13] drm: imx/dw_hdmi: move phy comments Russell King
2015-04-02 9:21 ` [PATCH RFC v2 02/13] drm: bridge/dw_hdmi: clean up phy configuration Russell King
2015-04-02 9:21 ` [PATCH RFC v2 03/13] drm: bridge/dw_hdmi: clean up hdmi_set_clk_regenerator() Russell King
2015-04-02 9:21 ` [PATCH RFC v2 04/13] drm: bridge/dw_hdmi: use drm_hdmi_avi_infoframe_from_display_mode() Russell King
2015-04-02 9:21 ` [PATCH RFC v2 05/13] drm: bridge/dw_hdmi: simplify hdmi_config_AVI() a little Russell King
2015-04-02 9:21 ` [PATCH RFC v2 06/13] drm: bridge/dw_hdmi: remove mhsyncpolarity/mvsyncpolarity/minterlaced Russell King
2015-04-02 9:21 ` [PATCH RFC v2 07/13] drm: bridge/dw_hdmi: introduce interface to setting sample rate Russell King
2015-04-02 9:21 ` [PATCH RFC v2 08/13] drm: bridge/dw_hdmi: introduce interfaces to enable and disable audio Russell King
2015-04-02 9:22 ` [PATCH RFC v2 09/13] drm/edid: add function to help find SADs Russell King
2015-04-02 9:22 ` [PATCH RFC v2 10/13] sound/core: add DRM ELD helper Russell King
2015-04-05 15:57 ` Takashi Iwai
2015-04-05 16:20 ` Russell King - ARM Linux
2015-04-05 16:46 ` Takashi Iwai
2015-04-05 17:26 ` Russell King - ARM Linux
2015-05-06 17:02 ` Anssi Hannula
2015-05-07 10:41 ` Russell King - ARM Linux
2015-05-07 11:11 ` Lars-Peter Clausen
2015-05-08 10:56 ` [alsa-devel] " Jyri Sarha
2015-05-08 11:42 ` Russell King - ARM Linux
2015-05-05 22:35 ` Mark Brown
2015-05-06 8:58 ` Liam Girdwood
2015-05-08 13:16 ` [alsa-devel] " Jyri Sarha
2015-05-08 13:27 ` Russell King - ARM Linux
2015-05-08 13:37 ` Jyri Sarha
2015-04-02 9:22 ` [PATCH RFC v2 11/13] sound/core: add IEC958 channel status helper Russell King
2015-04-02 9:22 ` [PATCH RFC v2 12/13] drm: bridge/dw_hdmi-ahb-audio: add audio driver Russell King
2015-04-02 9:22 ` [PATCH RFC v2 13/13] drm: bridge/dw_hdmi-ahb-audio: parse ELD from HDMI driver Russell King
2015-05-09 10:25 ` [PATCH v3 0/13] dw_hdmi cleanups, audio preparation, helpers and ahb audio support Russell King - ARM Linux
2015-05-09 10:25 ` [PATCH 01/13] drm: imx/dw_hdmi: move phy comments Russell King
2015-05-09 10:26 ` [PATCH 02/13] drm: bridge/dw_hdmi: clean up phy configuration Russell King
2015-05-22 15:19 ` Yakir
2015-05-09 10:26 ` [PATCH 03/13] drm: bridge/dw_hdmi: clean up hdmi_set_clk_regenerator() Russell King
2015-05-22 15:22 ` Yakir
2015-05-09 10:26 ` [PATCH 04/13] drm: bridge/dw_hdmi: use drm_hdmi_avi_infoframe_from_display_mode() Russell King
2015-05-09 10:26 ` [PATCH 05/13] drm: bridge/dw_hdmi: simplify hdmi_config_AVI() a little Russell King
2015-05-09 10:26 ` [PATCH 06/13] drm: bridge/dw_hdmi: remove mhsyncpolarity/mvsyncpolarity/minterlaced Russell King
2015-05-09 10:26 ` [PATCH 07/13] drm: bridge/dw_hdmi: introduce interface to setting sample rate Russell King
2015-05-22 15:26 ` Yakir
2015-05-09 10:26 ` [PATCH 08/13] drm: bridge/dw_hdmi: introduce interfaces to enable and disable audio Russell King
2015-05-22 15:28 ` Yakir [this message]
2015-05-09 10:26 ` [PATCH 09/13] drm/edid: add function to help find SADs Russell King
2015-05-09 10:26 ` [PATCH 10/13] sound/core: add DRM ELD helper Russell King
2015-05-22 12:20 ` [alsa-devel] " Mark Brown
2015-05-22 13:15 ` Russell King - ARM Linux
2015-05-22 13:30 ` Takashi Iwai
2015-05-22 13:53 ` Russell King - ARM Linux
2015-05-22 13:54 ` Takashi Iwai
2015-05-22 14:00 ` Russell King - ARM Linux
2015-05-22 14:02 ` Takashi Iwai
2015-05-22 14:05 ` Takashi Iwai
2015-05-22 16:12 ` Russell King - ARM Linux
2015-05-09 10:26 ` [PATCH 11/13] sound/core: add IEC958 channel status helper Russell King
2015-05-22 12:40 ` Mark Brown
2015-05-09 10:26 ` [PATCH 12/13] drm: bridge/dw_hdmi-ahb-audio: add audio driver Russell King
2015-05-09 16:49 ` [alsa-devel] " Anssi Hannula
2015-05-09 16:55 ` Russell King - ARM Linux
2015-05-09 17:07 ` Anssi Hannula
2015-05-09 17:40 ` Russell King - ARM Linux
2015-05-09 17:53 ` Russell King - ARM Linux
2015-05-09 17:55 ` Anssi Hannula
2015-05-09 18:11 ` Russell King - ARM Linux
2015-05-10 18:59 ` Anssi Hannula
2015-05-10 19:33 ` Russell King - ARM Linux
2015-05-10 20:47 ` Anssi Hannula
2015-05-11 15:58 ` Mark Brown
2015-05-09 10:26 ` [PATCH 13/13] drm: bridge/dw_hdmi-ahb-audio: parse ELD from HDMI driver Russell King
2015-05-27 10:43 ` Daniel Vetter
2015-05-27 11:43 ` Mark Brown
2015-05-27 17:31 ` Russell King - ARM Linux
2015-05-27 21:29 ` Daniel Vetter
2015-05-27 21:44 ` Russell King - ARM Linux
2015-05-28 6:43 ` Daniel Vetter
2015-05-28 4:56 ` [alsa-devel] " Takashi Iwai
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=555F4B3A.3070907@rock-chips.com \
--to=ykk@rock-chips.com \
--cc=airlied@linux.ie \
--cc=alsa-devel@alsa-project.org \
--cc=broonie@kernel.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=fabio.estevam@freescale.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=p.zabel@pengutronix.de \
--cc=rmk+kernel@arm.linux.org.uk \
--cc=tiwai@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).