From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9DFBBC10F14 for ; Tue, 15 Oct 2019 09:51:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 70CE920659 for ; Tue, 15 Oct 2019 09:51:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729827AbfJOJvf (ORCPT ); Tue, 15 Oct 2019 05:51:35 -0400 Received: from smtp1.goneo.de ([85.220.129.30]:45392 "EHLO smtp1.goneo.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726525AbfJOJve (ORCPT ); Tue, 15 Oct 2019 05:51:34 -0400 Received: from localhost (localhost [127.0.0.1]) by smtp1.goneo.de (Postfix) with ESMTP id 85B6D23F4B8; Tue, 15 Oct 2019 11:51:30 +0200 (CEST) X-Virus-Scanned: by goneo Received: from smtp1.goneo.de ([127.0.0.1]) by localhost (smtp1.goneo.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id sBGS03dGLi35; Tue, 15 Oct 2019 11:51:29 +0200 (CEST) Received: from lem-wkst-02.lemonage (hq.lemonage.de [87.138.178.34]) by smtp1.goneo.de (Postfix) with ESMTPSA id 7CE9423F856; Tue, 15 Oct 2019 11:51:28 +0200 (CEST) Date: Tue, 15 Oct 2019 11:51:24 +0200 From: Lars Poeschel To: Jakub Kicinski Cc: Jilayne Lovejoy , Kate Stewart , Allison Randal , Greg Kroah-Hartman , Thomas Gleixner , Steve Winslow , "Gustavo A. R. Silva" , Johan Hovold , "open list:NFC SUBSYSTEM" , open list , Claudiu Beznea Subject: Re: [PATCH v9 4/7] nfc: pn533: Split pn533 init & nfc_register Message-ID: <20191015095124.GA17778@lem-wkst-02.lemonage> References: <20191008140544.17112-1-poeschel@lemonage.de> <20191008140544.17112-5-poeschel@lemonage.de> <20191009174023.528c278b@cakuba.netronome.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191009174023.528c278b@cakuba.netronome.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Oct 09, 2019 at 05:40:23PM -0700, Jakub Kicinski wrote: > On Tue, 8 Oct 2019 16:05:41 +0200, 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 > > Cc: Claudiu Beznea > > Signed-off-by: Lars Poeschel > > > 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); > > nit: start of continuation lines should match the opening parenthesis, > please run checkpatch and fix the style issue Ok, I will change that. > > 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..e5d5e4c83a04 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; > > Aren't you moving too much out of here? Looking at commit 32ecc75ded72 > ("NFC: pn533: change order operations in dev registation") it seems like > IRQ handler may want to access the data structures, do this change not > reintroduce the problem? Yes, you are right, there could be a problem if an irq gets served before the driver is registered to the nfc subsystem. Well, but the purpose of this patch is exactly that: Prevent use of nfc subsystem before the chip is fully initialized. To address this, I would not change the part above, but move the request_threaded_irq to the very bottom in pn533_i2c_probe, after the call to pn53x_register_nfc. So it is not possible to use nfc before the chip is initialized and irqs don't get served before the driver is registered to nfc subsystem. Thank you for this! I will include this in v10 of the patchset. > > 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); > > >