On Fri, Jun 13, 2014 at 05:56:02PM +0200, Takashi Iwai wrote:
> When a machine is booted with nomodeset option, i915 driver skips the
> whole initialization. Meanwhile, HD-audio tries to bind wth i915 just
> by request_symbol() without knowing that the initialization was
> skipped, and eventually it hits WARN_ON() in i915_request_power_well()
> and i915_release_power_well() wrongly but still continues probing,
> even though it doesn't work at all.
>
> In this patch, both functions are changed to return an error in case
> of uninitialized state instead of WARN_ON(), so that HD-audio driver
> can give up HDMI controller initialization at the right time.
>
> Cc: <stable@xxxxxxxxxxxxxxx> [3.15]
> Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
I guess you'll merge this through the sound tree?
-Daniel
> ---
>
> The bug actually exists since 3.11, but this commit will be applicable
> only to recent kernels due to ALSA and i915 code changes, that's why
> marked with [3.15] for stable.
>
> drivers/gpu/drm/i915/intel_pm.c | 14 ++++++++------
> include/drm/i915_powerwell.h | 4 ++--
> sound/pci/hda/hda_i915.c | 12 ++++++------
> sound/pci/hda/hda_i915.h | 4 ++--
> sound/pci/hda/hda_intel.c | 7 ++++++-
> 5 files changed, 24 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index d93dcf683e8c..0d6bd247009b 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -5706,30 +5706,32 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
> static struct i915_power_domains *hsw_pwr;
>
> /* Display audio driver power well request */
> -void i915_request_power_well(void)
> +int i915_request_power_well(void)
> {
> struct drm_i915_private *dev_priv;
>
> - if (WARN_ON(!hsw_pwr))
> - return;
> + if (!hsw_pwr)
> + return -ENODEV;
>
> dev_priv = container_of(hsw_pwr, struct drm_i915_private,
> power_domains);
> intel_display_power_get(dev_priv, POWER_DOMAIN_AUDIO);
> + return 0;
> }
> EXPORT_SYMBOL_GPL(i915_request_power_well);
>
> /* Display audio driver power well release */
> -void i915_release_power_well(void)
> +int i915_release_power_well(void)
> {
> struct drm_i915_private *dev_priv;
>
> - if (WARN_ON(!hsw_pwr))
> - return;
> + if (!hsw_pwr)
> + return -ENODEV;
>
> dev_priv = container_of(hsw_pwr, struct drm_i915_private,
> power_domains);
> intel_display_power_put(dev_priv, POWER_DOMAIN_AUDIO);
> + return 0;
> }
> EXPORT_SYMBOL_GPL(i915_release_power_well);
>
> diff --git a/include/drm/i915_powerwell.h b/include/drm/i915_powerwell.h
> index cfdc884405b7..2baba9996094 100644
> --- a/include/drm/i915_powerwell.h
> +++ b/include/drm/i915_powerwell.h
> @@ -30,7 +30,7 @@
> #define _I915_POWERWELL_H_
>
> /* For use by hda_i915 driver */
> -extern void i915_request_power_well(void);
> -extern void i915_release_power_well(void);
> +extern int i915_request_power_well(void);
> +extern int i915_release_power_well(void);
>
> #endif /* _I915_POWERWELL_H_ */
> diff --git a/sound/pci/hda/hda_i915.c b/sound/pci/hda/hda_i915.c
> index 9d07e4edacdb..e9e8a4a4a9a1 100644
> --- a/sound/pci/hda/hda_i915.c
> +++ b/sound/pci/hda/hda_i915.c
> @@ -22,20 +22,20 @@
> #include <drm/i915_powerwell.h>
> #include "hda_i915.h"
>
> -static void (*get_power)(void);
> -static void (*put_power)(void);
> +static int (*get_power)(void);
> +static int (*put_power)(void);
>
> -void hda_display_power(bool enable)
> +int hda_display_power(bool enable)
> {
> if (!get_power || !put_power)
> - return;
> + return -ENODEV;
>
> pr_debug("HDA display power %s \n",
> enable ? "Enable" : "Disable");
> if (enable)
> - get_power();
> + return get_power();
> else
> - put_power();
> + return put_power();
> }
>
> int hda_i915_init(void)
> diff --git a/sound/pci/hda/hda_i915.h b/sound/pci/hda/hda_i915.h
> index 5a63da2c53e5..bfd835f8f1aa 100644
> --- a/sound/pci/hda/hda_i915.h
> +++ b/sound/pci/hda/hda_i915.h
> @@ -17,11 +17,11 @@
> #define __SOUND_HDA_I915_H
>
> #ifdef CONFIG_SND_HDA_I915
> -void hda_display_power(bool enable);
> +int hda_display_power(bool enable);
> int hda_i915_init(void);
> int hda_i915_exit(void);
> #else
> -static inline void hda_display_power(bool enable) {}
> +static inline int hda_display_power(bool enable) { return 0; }
> static inline int hda_i915_init(void)
> {
> return -ENODEV;
> diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
> index bb65a124e006..23fd6b9aecca 100644
> --- a/sound/pci/hda/hda_intel.c
> +++ b/sound/pci/hda/hda_intel.c
> @@ -1656,8 +1656,13 @@ static int azx_probe_continue(struct azx *chip)
> "Error request power-well from i915\n");
> goto out_free;
> }
> + err = hda_display_power(true);
> + if (err < 0) {
> + dev_err(chip->card->dev,
> + "Cannot turn on display power on i915\n");
> + goto out_free;
> + }
> #endif
> - hda_display_power(true);
> }
>
> err = azx_first_init(chip);
> --
> 1.9.3
>
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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