[PATCH RFC 03/10] drm/i2c: tda998x: avoid racy access to mode clock
Russell King
rmk+kernel at armlinux.org.uk
Sun Oct 23 12:10:39 PDT 2016
Avoid a racy access to the mode clock by storing the current mode clock
during a mode set under the audio mutex. This allows us to access it
from the audio path in a safe way.
Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
---
drivers/gpu/drm/i2c/tda998x_drv.c | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c
index 495ee3fed661..858237f7f4d6 100644
--- a/drivers/gpu/drm/i2c/tda998x_drv.c
+++ b/drivers/gpu/drm/i2c/tda998x_drv.c
@@ -48,6 +48,7 @@ struct tda998x_priv {
u8 vip_cntrl_0;
u8 vip_cntrl_1;
u8 vip_cntrl_2;
+ unsigned long tdms_clock;
struct tda998x_audio_params audio_params;
struct platform_device *audio_pdev;
@@ -714,8 +715,7 @@ static void tda998x_audio_mute(struct tda998x_priv *priv, bool on)
static int
tda998x_configure_audio(struct tda998x_priv *priv,
- struct tda998x_audio_params *params,
- unsigned mode_clock)
+ struct tda998x_audio_params *params)
{
u8 buf[6], clksel_aip, clksel_fs, cts_n, adiv;
u32 n;
@@ -772,7 +772,7 @@ tda998x_configure_audio(struct tda998x_priv *priv,
* assume 100MHz requires larger divider.
*/
adiv = AUDIO_DIV_SERCLK_8;
- if (mode_clock > 100000)
+ if (priv->tdms_clock > 100000)
adiv++; /* AUDIO_DIV_SERCLK_16 */
/* S/PDIF asks for a larger divider */
@@ -1077,10 +1077,10 @@ tda998x_encoder_mode_set(struct drm_encoder *encoder,
tda998x_write_avi(priv, adjusted_mode);
+ priv->tdms_clock = adjusted_mode->clock;
+
if (priv->audio_params.format != AFMT_UNUSED)
- tda998x_configure_audio(priv,
- &priv->audio_params,
- adjusted_mode->clock);
+ tda998x_configure_audio(priv, &priv->audio_params);
}
priv->is_hdmi_config = priv->is_hdmi_sink;
@@ -1230,9 +1230,6 @@ static int tda998x_audio_hw_params(struct device *dev, void *data,
.cea = params->cea,
};
- if (!priv->encoder.crtc)
- return -ENODEV;
-
memcpy(audio.status, params->iec.status,
min(sizeof(audio.status), sizeof(params->iec.status)));
@@ -1270,8 +1267,7 @@ static int tda998x_audio_hw_params(struct device *dev, void *data,
mutex_lock(&priv->audio_mutex);
/* We must not program the TDA998x for audio if the sink is DVI. */
if (priv->is_hdmi_config)
- ret = tda998x_configure_audio(priv, &audio,
- priv->encoder.crtc->hwmode.clock);
+ ret = tda998x_configure_audio(priv, &audio);
else
ret = 0;
--
2.1.0
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