From 47677e51e2a4040c204d7971a5103592600185b1 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Wed, 5 Mar 2014 11:21:07 -0300 Subject: [PATCH] [media] em28xx: Only deallocate struct em28xx after finishing all extensions MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We can't free struct em28xx while one of the extensions is still using it. So, add a kref() to control it, freeing it only after the extensions fini calls. Reviewed-by: Frank Schäfer Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/em28xx/em28xx-audio.c | 7 +++++- drivers/media/usb/em28xx/em28xx-cards.c | 32 +++++++++++++++++++------ drivers/media/usb/em28xx/em28xx-dvb.c | 5 +++- drivers/media/usb/em28xx/em28xx-input.c | 8 ++++++- drivers/media/usb/em28xx/em28xx-video.c | 15 ++++++------ drivers/media/usb/em28xx/em28xx.h | 8 +++++-- 6 files changed, 56 insertions(+), 19 deletions(-) diff --git a/drivers/media/usb/em28xx/em28xx-audio.c b/drivers/media/usb/em28xx/em28xx-audio.c index 0f5b6f3e7a3..f75c0a5494d 100644 --- a/drivers/media/usb/em28xx/em28xx-audio.c +++ b/drivers/media/usb/em28xx/em28xx-audio.c @@ -301,6 +301,7 @@ static int snd_em28xx_capture_open(struct snd_pcm_substream *substream) goto err; } + kref_get(&dev->ref); dev->adev.users++; mutex_unlock(&dev->lock); @@ -341,6 +342,7 @@ static int snd_em28xx_pcm_close(struct snd_pcm_substream *substream) substream->runtime->dma_area = NULL; } mutex_unlock(&dev->lock); + kref_put(&dev->ref, em28xx_free_device); return 0; } @@ -895,6 +897,8 @@ static int em28xx_audio_init(struct em28xx *dev) em28xx_info("Binding audio extension\n"); + kref_get(&dev->ref); + printk(KERN_INFO "em28xx-audio.c: Copyright (C) 2006 Markus " "Rechberger\n"); printk(KERN_INFO @@ -967,7 +971,7 @@ static int em28xx_audio_fini(struct em28xx *dev) if (dev == NULL) return 0; - if (dev->has_alsa_audio != 1) { + if (!dev->has_alsa_audio) { /* This device does not support the extension (in this case the device is expecting the snd-usb-audio module or doesn't have analog audio support at all) */ @@ -986,6 +990,7 @@ static int em28xx_audio_fini(struct em28xx *dev) dev->adev.sndcard = NULL; } + kref_put(&dev->ref, em28xx_free_device); return 0; } diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c index 2fb300e882f..e7ec3b7866f 100644 --- a/drivers/media/usb/em28xx/em28xx-cards.c +++ b/drivers/media/usb/em28xx/em28xx-cards.c @@ -2939,7 +2939,7 @@ static void flush_request_modules(struct em28xx *dev) * unregisters the v4l2,i2c and usb devices * called when the device gets disconnected or at module unload */ -void em28xx_release_resources(struct em28xx *dev) +static void em28xx_release_resources(struct em28xx *dev) { /*FIXME: I2C IR should be disconnected */ @@ -2956,7 +2956,27 @@ void em28xx_release_resources(struct em28xx *dev) mutex_unlock(&dev->lock); }; -EXPORT_SYMBOL_GPL(em28xx_release_resources); + +/** + * em28xx_free_device() - Free em28xx device + * + * @ref: struct kref for em28xx device + * + * This is called when all extensions and em28xx core unregisters a device + */ +void em28xx_free_device(struct kref *ref) +{ + struct em28xx *dev = kref_to_dev(ref); + + em28xx_info("Freeing device\n"); + + if (!dev->disconnected) + em28xx_release_resources(dev); + + kfree(dev->alt_max_pkt_size_isoc); + kfree(dev); +} +EXPORT_SYMBOL_GPL(em28xx_free_device); /* * em28xx_init_dev() @@ -3409,6 +3429,8 @@ static int em28xx_usb_probe(struct usb_interface *interface, dev->dvb_xfer_bulk ? "bulk" : "isoc"); } + kref_init(&dev->ref); + request_modules(dev); /* Should be the last thing to do, to avoid newer udev's to @@ -3453,11 +3475,7 @@ static void em28xx_usb_disconnect(struct usb_interface *interface) em28xx_close_extension(dev); em28xx_release_resources(dev); - - if (!dev->users) { - kfree(dev->alt_max_pkt_size_isoc); - kfree(dev); - } + kref_put(&dev->ref, em28xx_free_device); } static int em28xx_usb_suspend(struct usb_interface *interface, diff --git a/drivers/media/usb/em28xx/em28xx-dvb.c b/drivers/media/usb/em28xx/em28xx-dvb.c index d4986bdfbdc..cacdca3a341 100644 --- a/drivers/media/usb/em28xx/em28xx-dvb.c +++ b/drivers/media/usb/em28xx/em28xx-dvb.c @@ -1043,7 +1043,6 @@ static int em28xx_dvb_init(struct em28xx *dev) em28xx_info("Binding DVB extension\n"); dvb = kzalloc(sizeof(struct em28xx_dvb), GFP_KERNEL); - if (dvb == NULL) { em28xx_info("em28xx_dvb: memory allocation failed\n"); return -ENOMEM; @@ -1521,6 +1520,9 @@ static int em28xx_dvb_init(struct em28xx *dev) dvb->adapter.mfe_shared = mfe_shared; em28xx_info("DVB extension successfully initialized\n"); + + kref_get(&dev->ref); + ret: em28xx_set_mode(dev, EM28XX_SUSPEND); mutex_unlock(&dev->lock); @@ -1577,6 +1579,7 @@ static int em28xx_dvb_fini(struct em28xx *dev) em28xx_unregister_dvb(dvb); kfree(dvb); dev->dvb = NULL; + kref_put(&dev->ref, em28xx_free_device); } return 0; diff --git a/drivers/media/usb/em28xx/em28xx-input.c b/drivers/media/usb/em28xx/em28xx-input.c index 47a2c1dcccb..2a9bf667f20 100644 --- a/drivers/media/usb/em28xx/em28xx-input.c +++ b/drivers/media/usb/em28xx/em28xx-input.c @@ -676,6 +676,8 @@ static int em28xx_ir_init(struct em28xx *dev) return 0; } + kref_get(&dev->ref); + if (dev->board.buttons) em28xx_init_buttons(dev); @@ -816,7 +818,7 @@ static int em28xx_ir_fini(struct em28xx *dev) /* skip detach on non attached boards */ if (!ir) - return 0; + goto ref_put; if (ir->rc) rc_unregister_device(ir->rc); @@ -824,6 +826,10 @@ static int em28xx_ir_fini(struct em28xx *dev) /* done */ kfree(ir); dev->ir = NULL; + +ref_put: + kref_put(&dev->ref, em28xx_free_device); + return 0; } diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c index 13466c47023..0856e5d367b 100644 --- a/drivers/media/usb/em28xx/em28xx-video.c +++ b/drivers/media/usb/em28xx/em28xx-video.c @@ -1837,7 +1837,6 @@ static int em28xx_v4l2_open(struct file *filp) video_device_node_name(vdev), v4l2_type_names[fh_type], dev->users); - if (mutex_lock_interruptible(&dev->lock)) return -ERESTARTSYS; fh = kzalloc(sizeof(struct em28xx_fh), GFP_KERNEL); @@ -1869,6 +1868,7 @@ static int em28xx_v4l2_open(struct file *filp) v4l2_device_call_all(&dev->v4l2_dev, 0, tuner, s_radio); } + kref_get(&dev->ref); dev->users++; mutex_unlock(&dev->lock); @@ -1926,9 +1926,8 @@ static int em28xx_v4l2_fini(struct em28xx *dev) dev->clk = NULL; } - if (dev->users) - em28xx_warn("Device is open ! Memory deallocation is deferred on last close.\n"); mutex_unlock(&dev->lock); + kref_put(&dev->ref, em28xx_free_device); return 0; } @@ -1976,11 +1975,9 @@ static int em28xx_v4l2_close(struct file *filp) mutex_lock(&dev->lock); if (dev->users == 1) { - /* free the remaining resources if device is disconnected */ - if (dev->disconnected) { - kfree(dev->alt_max_pkt_size_isoc); + /* No sense to try to write to the device */ + if (dev->disconnected) goto exit; - } /* Save some power by putting tuner to sleep */ v4l2_device_call_all(&dev->v4l2_dev, 0, core, s_power, 0); @@ -2001,6 +1998,8 @@ static int em28xx_v4l2_close(struct file *filp) exit: dev->users--; mutex_unlock(&dev->lock); + kref_put(&dev->ref, em28xx_free_device); + return 0; } @@ -2515,6 +2514,8 @@ static int em28xx_v4l2_init(struct em28xx *dev) em28xx_info("V4L2 extension successfully initialized\n"); + kref_get(&dev->ref); + mutex_unlock(&dev->lock); return 0; diff --git a/drivers/media/usb/em28xx/em28xx.h b/drivers/media/usb/em28xx/em28xx.h index 9e44f5bfc48..2051fc9fb93 100644 --- a/drivers/media/usb/em28xx/em28xx.h +++ b/drivers/media/usb/em28xx/em28xx.h @@ -32,6 +32,7 @@ #include #include #include +#include #include #include @@ -536,9 +537,10 @@ struct em28xx_i2c_bus { enum em28xx_i2c_algo_type algo_type; }; - /* main device struct */ struct em28xx { + struct kref ref; + /* generic device properties */ char name[30]; /* name (including minor) of the device */ int model; /* index in the device_data struct */ @@ -710,6 +712,8 @@ struct em28xx { struct em28xx_dvb *dvb; }; +#define kref_to_dev(d) container_of(d, struct em28xx, ref) + struct em28xx_ops { struct list_head next; char *name; @@ -771,7 +775,7 @@ extern struct em28xx_board em28xx_boards[]; extern struct usb_device_id em28xx_id_table[]; int em28xx_tuner_callback(void *ptr, int component, int command, int arg); void em28xx_setup_xc3028(struct em28xx *dev, struct xc2028_ctrl *ctl); -void em28xx_release_resources(struct em28xx *dev); +void em28xx_free_device(struct kref *ref); /* Provided by em28xx-camera.c */ int em28xx_detect_sensor(struct em28xx *dev); -- 2.46.0