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Date:   Fri, 23 Aug 2019 11:07:40 +0200
From:   Lars Poeschel <poeschel@lemonage.de>
To:     Claudiu.Beznea@microchip.com
Cc:     gregkh@linuxfoundation.org, allison@lohutok.net,
        swinslow@gmail.com, tglx@linutronix.de,
        kstewart@linuxfoundation.org, gustavo@embeddedor.com,
        keescook@chromium.org, opensource@jilayne.com,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        johan@kernel.org
Subject: Re: [PATCH v6 4/7] nfc: pn533: Split pn533 init & nfc_register
Message-ID: <20190823090740.GA14401@lem-wkst-02.lemonage>
References: <20190820120345.22593-1-poeschel@lemonage.de>
 <20190820120345.22593-4-poeschel@lemonage.de>
 <67dbe5a1-35e7-0ac9-efbc-6425b3628b18@microchip.com>
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On Thu, Aug 22, 2019 at 10:08:40AM +0000, Claudiu.Beznea@microchip.com wrote:
> 
> 
> On 20.08.2019 15:03, Lars Poeschel wrote:
> > There is a problem in the initialisation and setup of the pn533: It
> > registers with nfc too early. It could happen, that it finished
> > registering with nfc and someone starts using it. But setup of the pn533
> > is not yet finished. Bad or at least unintended things could happen.
> > So I split out nfc registering (and unregistering) to seperate functions
> > that have to be called late in probe then.
> > 
> > Cc: Johan Hovold <johan@kernel.org>
> > Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
> > ---
> > Changes in v6:
> > - Rebased the patch series on v5.3-rc5
> > 
> > Changes in v5:
> > - This patch is new in v5
> > 
> >  drivers/nfc/pn533/i2c.c   | 17 +++++-----
> >  drivers/nfc/pn533/pn533.c | 66 ++++++++++++++++++++-------------------
> >  drivers/nfc/pn533/pn533.h | 11 ++++---
> >  drivers/nfc/pn533/usb.c   | 12 +++++--
> >  4 files changed, 59 insertions(+), 47 deletions(-)
> > 
> > diff --git a/drivers/nfc/pn533/i2c.c b/drivers/nfc/pn533/i2c.c
> > index 1abd40398a5a..e9e5a1ec8857 100644
> > --- a/drivers/nfc/pn533/i2c.c
> > +++ b/drivers/nfc/pn533/i2c.c
> > @@ -193,12 +193,10 @@ static int pn533_i2c_probe(struct i2c_client *client,
> >  	phy->i2c_dev = client;
> >  	i2c_set_clientdata(client, phy);
> >  
> > -	priv = pn533_register_device(PN533_DEVICE_PN532,
> > -				     PN533_NO_TYPE_B_PROTOCOLS,
> > +	priv = pn53x_common_init(PN533_DEVICE_PN532,
> >  				     PN533_PROTO_REQ_ACK_RESP,
> >  				     phy, &i2c_phy_ops, NULL,
> > -				     &phy->i2c_dev->dev,
> > -				     &client->dev);
> > +				     &phy->i2c_dev->dev);
> >  
> >  	if (IS_ERR(priv)) {
> >  		r = PTR_ERR(priv);
> > @@ -220,13 +218,17 @@ static int pn533_i2c_probe(struct i2c_client *client,
> >  	if (r)
> >  		goto fn_setup_err;
> >  
> > -	return 0;
> > +	r = pn53x_register_nfc(priv, PN533_NO_TYPE_B_PROTOCOLS, &client->dev);
> > +	if (r)
> > +		goto fn_setup_err;
> > +
> > +	return r;
> >  
> >  fn_setup_err:
> >  	free_irq(client->irq, phy);
> >  
> >  irq_rqst_err:
> > -	pn533_unregister_device(phy->priv);
> > +	pn53x_common_clean(phy->priv);
> >  
> >  	return r;
> >  }
> > @@ -239,7 +241,8 @@ static int pn533_i2c_remove(struct i2c_client *client)
> >  
> >  	free_irq(client->irq, phy);
> >  
> > -	pn533_unregister_device(phy->priv);
> > +	pn53x_unregister_nfc(phy->priv);
> > +	pn53x_common_clean(phy->priv);
> >  
> >  	return 0;
> >  }
> > diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c
> > index 64836c727aee..a8c756caa678 100644
> > --- a/drivers/nfc/pn533/pn533.c
> > +++ b/drivers/nfc/pn533/pn533.c
> > @@ -2590,14 +2590,12 @@ int pn533_finalize_setup(struct pn533 *dev)
> >  }
> >  EXPORT_SYMBOL_GPL(pn533_finalize_setup);
> >  
> > -struct pn533 *pn533_register_device(u32 device_type,
> > -				u32 protocols,
> > +struct pn533 *pn53x_common_init(u32 device_type,
> >  				enum pn533_protocol_type protocol_type,
> >  				void *phy,
> >  				struct pn533_phy_ops *phy_ops,
> >  				struct pn533_frame_ops *fops,
> > -				struct device *dev,
> > -				struct device *parent)
> > +				struct device *dev)
> >  {
> >  	struct pn533 *priv;
> >  	int rc = -ENOMEM;
> > @@ -2638,43 +2636,18 @@ struct pn533 *pn533_register_device(u32 device_type,
> >  	skb_queue_head_init(&priv->fragment_skb);
> >  
> >  	INIT_LIST_HEAD(&priv->cmd_queue);
> > -
> > -	priv->nfc_dev = nfc_allocate_device(&pn533_nfc_ops, protocols,
> > -					   priv->ops->tx_header_len +
> > -					   PN533_CMD_DATAEXCH_HEAD_LEN,
> > -					   priv->ops->tx_tail_len);
> > -	if (!priv->nfc_dev) {
> > -		rc = -ENOMEM;
> > -		goto destroy_wq;
> > -	}
> > -
> > -	nfc_set_parent_dev(priv->nfc_dev, parent);
> > -	nfc_set_drvdata(priv->nfc_dev, priv);
> > -
> > -	rc = nfc_register_device(priv->nfc_dev);
> > -	if (rc)
> > -		goto free_nfc_dev;
> > -
> >  	return priv;
> >  
> > -free_nfc_dev:
> > -	nfc_free_device(priv->nfc_dev);
> > -
> > -destroy_wq:
> > -	destroy_workqueue(priv->wq);
> >  error:
> >  	kfree(priv);
> >  	return ERR_PTR(rc);
> >  }
> > -EXPORT_SYMBOL_GPL(pn533_register_device);
> > +EXPORT_SYMBOL_GPL(pn53x_common_init);
> >  
> > -void pn533_unregister_device(struct pn533 *priv)
> > +void pn53x_common_clean(struct pn533 *priv)
> >  {
> >  	struct pn533_cmd *cmd, *n;
> >  
> > -	nfc_unregister_device(priv->nfc_dev);
> > -	nfc_free_device(priv->nfc_dev);
> > -
> >  	flush_delayed_work(&priv->poll_work);
> >  	destroy_workqueue(priv->wq);
> >  
> > @@ -2689,8 +2662,37 @@ void pn533_unregister_device(struct pn533 *priv)
> >  
> >  	kfree(priv);
> >  }
> > -EXPORT_SYMBOL_GPL(pn533_unregister_device);
> > +EXPORT_SYMBOL_GPL(pn53x_common_clean);
> > +
> > +int pn53x_register_nfc(struct pn533 *priv, u32 protocols,
> > +			struct device *parent)
> > +{
> > +	int rc = -ENOMEM;
> 
> No need to initialize rc here... or just return rc below.

I will remove the initialization. Looks better to me.

> > +
> > +	priv->nfc_dev = nfc_allocate_device(&pn533_nfc_ops, protocols,
> > +					   priv->ops->tx_header_len +
> > +					   PN533_CMD_DATAEXCH_HEAD_LEN,
> > +					   priv->ops->tx_tail_len);
> > +	if (!priv->nfc_dev)
> > +		return -ENOMEM;
> > +
> > +	nfc_set_parent_dev(priv->nfc_dev, parent);
> > +	nfc_set_drvdata(priv->nfc_dev, priv);
> > +
> > +	rc = nfc_register_device(priv->nfc_dev);
> > +	if (rc)
> > +		nfc_free_device(priv->nfc_dev);
> > +
> > +	return rc;
> > +}
> > +EXPORT_SYMBOL_GPL(pn53x_register_nfc);
> >  
> > +void pn53x_unregister_nfc(struct pn533 *priv)
> > +{
> > +	nfc_unregister_device(priv->nfc_dev);
> > +	nfc_free_device(priv->nfc_dev);
> > +}
> > +EXPORT_SYMBOL_GPL(pn53x_unregister_nfc);
> >  
> >  MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>");
> >  MODULE_AUTHOR("Aloisio Almeida Jr <aloisio.almeida@openbossa.org>");
> > diff --git a/drivers/nfc/pn533/pn533.h b/drivers/nfc/pn533/pn533.h
> > index 570ee0a3e832..510ddebbd896 100644
> > --- a/drivers/nfc/pn533/pn533.h
> > +++ b/drivers/nfc/pn533/pn533.h
> > @@ -219,18 +219,19 @@ struct pn533_phy_ops {
> >  };
> >  
> >  
> > -struct pn533 *pn533_register_device(u32 device_type,
> > -				u32 protocols,
> > +struct pn533 *pn53x_common_init(u32 device_type,
> >  				enum pn533_protocol_type protocol_type,
> >  				void *phy,
> >  				struct pn533_phy_ops *phy_ops,
> >  				struct pn533_frame_ops *fops,
> > -				struct device *dev,
> > -				struct device *parent);
> > +				struct device *dev);
> >  
> >  int pn533_finalize_setup(struct pn533 *dev);
> > -void pn533_unregister_device(struct pn533 *priv);
> > +void pn53x_common_clean(struct pn533 *priv);
> >  void pn533_recv_frame(struct pn533 *dev, struct sk_buff *skb, int status);
> > +int pn53x_register_nfc(struct pn533 *priv, u32 protocols,
> > +			struct device *parent);
> > +void pn53x_unregister_nfc(struct pn533 *priv);
> >  
> >  bool pn533_rx_frame_is_cmd_response(struct pn533 *dev, void *frame);
> >  bool pn533_rx_frame_is_ack(void *_frame);
> > diff --git a/drivers/nfc/pn533/usb.c b/drivers/nfc/pn533/usb.c
> > index c5289eaf17ee..a1c6a41944c6 100644
> > --- a/drivers/nfc/pn533/usb.c
> > +++ b/drivers/nfc/pn533/usb.c
> > @@ -534,9 +534,9 @@ static int pn533_usb_probe(struct usb_interface *interface,
> >  		goto error;
> >  	}
> >  
> > -	priv = pn533_register_device(id->driver_info, protocols, protocol_type,
> > +	priv = pn53x_common_init(id->driver_info, protocol_type,
> >  					phy, &usb_phy_ops, fops,
> > -					&phy->udev->dev, &interface->dev);
> > +					&phy->udev->dev);
> >  
> >  	if (IS_ERR(priv)) {
> >  		rc = PTR_ERR(priv);
> > @@ -550,9 +550,14 @@ static int pn533_usb_probe(struct usb_interface *interface,
> >  		goto error;
> >  
> >  	usb_set_intfdata(interface, phy);
> 
> Above this instruction there is this code:
> 
> 	rc = pn533_finalize_setup(priv);
> 	if (rc)
> 		goto error;
> 
> Instead of "goto error;" you should have "goto err_clean;"

Thank you for catching this one. I will change it.

> > +	rc = pn53x_register_nfc(priv, protocols, &interface->dev);
> > +	if (rc)
> > +		goto err_clean;
> >  
> >  	return 0;
> >  
> > +err_clean:
> > +	pn53x_common_clean(priv);
> >  error:
> >  	usb_free_urb(phy->in_urb);
> >  	usb_free_urb(phy->out_urb);
> > @@ -570,7 +575,8 @@ static void pn533_usb_disconnect(struct usb_interface *interface)
> >  	if (!phy)
> >  		return;
> >  
> > -	pn533_unregister_device(phy->priv);
> > +	pn53x_unregister_nfc(phy->priv);
> > +	pn53x_common_clean(phy->priv);
> >  
> >  	usb_set_intfdata(interface, NULL);
> >  
> >