diff options
| -rw-r--r-- | drivers/gpu/drm/vc4/vc4_hdmi.c | 43 |
1 files changed, 36 insertions, 7 deletions
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index 283fea78f3cf..bf7d56bbcba0 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -2056,6 +2056,14 @@ static struct hdmi_codec_pdata vc4_hdmi_codec_pdata = { .i2s = 1, }; +static void vc4_hdmi_audio_codec_release(void *ptr) +{ + struct vc4_hdmi *vc4_hdmi = ptr; + + platform_device_unregister(vc4_hdmi->audio.codec_pdev); + vc4_hdmi->audio.codec_pdev = NULL; +} + static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi) { const struct vc4_hdmi_register *mai_data = @@ -2097,6 +2105,30 @@ static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi) vc4_hdmi->audio.dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; vc4_hdmi->audio.dma_data.maxburst = 2; + /* + * NOTE: Strictly speaking, we should probably use a DRM-managed + * registration there to avoid removing all the audio components + * by the time the driver doesn't have any user anymore. + * + * However, the ASoC core uses a number of devm_kzalloc calls + * when registering, even when using non-device-managed + * functions (such as in snd_soc_register_component()). + * + * If we call snd_soc_unregister_component() in a DRM-managed + * action, the device-managed actions have already been executed + * and thus we would access memory that has been freed. + * + * Using device-managed hooks here probably leaves us open to a + * bunch of issues if userspace still has a handle on the ALSA + * device when the device is removed. However, this is mitigated + * by the use of drm_dev_enter()/drm_dev_exit() in the audio + * path to prevent the access to the device resources if it + * isn't there anymore. + * + * Then, the vc4_hdmi structure is DRM-managed and thus only + * freed whenever the last user has closed the DRM device file. + * It should thus outlive ALSA in most situations. + */ ret = devm_snd_dmaengine_pcm_register(dev, &pcm_conf, 0); if (ret) { dev_err(dev, "Could not register PCM component: %d\n", ret); @@ -2120,6 +2152,10 @@ static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi) } vc4_hdmi->audio.codec_pdev = codec_pdev; + ret = devm_add_action_or_reset(dev, vc4_hdmi_audio_codec_release, vc4_hdmi); + if (ret) + return ret; + dai_link->cpus = &vc4_hdmi->audio.cpu; dai_link->codecs = &vc4_hdmi->audio.codec; dai_link->platforms = &vc4_hdmi->audio.platform; @@ -2158,12 +2194,6 @@ static int vc4_hdmi_audio_init(struct vc4_hdmi *vc4_hdmi) } -static void vc4_hdmi_audio_exit(struct vc4_hdmi *vc4_hdmi) -{ - platform_device_unregister(vc4_hdmi->audio.codec_pdev); - vc4_hdmi->audio.codec_pdev = NULL; -} - static irqreturn_t vc4_hdmi_hpd_irq_thread(int irq, void *priv) { struct vc4_hdmi *vc4_hdmi = priv; @@ -3062,7 +3092,6 @@ static void vc4_hdmi_unbind(struct device *dev, struct device *master, kfree(vc4_hdmi->hdmi_regset.regs); kfree(vc4_hdmi->hd_regset.regs); - vc4_hdmi_audio_exit(vc4_hdmi); vc4_hdmi_cec_exit(vc4_hdmi); vc4_hdmi_hotplug_exit(vc4_hdmi); |