Re: [PATCH v6 4/7] nfc: pn533: Split pn533 init & nfc_register

From: Lars Poeschel
Date: Fri Aug 23 2019 - 04:54:52 EST


On Thu, Aug 22, 2019 at 10:08:40AM +0000, Claudiu.Beznea@xxxxxxxxxxxxx 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@xxxxxxxxxx>
> > Signed-off-by: Lars Poeschel <poeschel@xxxxxxxxxxx>
> > ---
> > 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@xxxxxxxxxxxxx>");
> > MODULE_AUTHOR("Aloisio Almeida Jr <aloisio.almeida@xxxxxxxxxxxxx>");
> > 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);
> >
> >