Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752847AbcLGJbU (ORCPT ); Wed, 7 Dec 2016 04:31:20 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:43230 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752142AbcLGJbT (ORCPT ); Wed, 7 Dec 2016 04:31:19 -0500 Date: Wed, 7 Dec 2016 10:31:24 +0100 From: Greg KH To: Chris Bostic Cc: robh+dt@kernel.org, mark.rutland@arm.com, linux@armlinux.org.uk, sre@kernel.org, mturquette@baylibre.com, geert+renesas@glider.be, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Chris Bostic , joel@jms.id.au, jk@ozlabs.org, linux-kernel@vger.kernel.org, andrew@aj.id.au, alistair@popple.id.au, benh@kernel.crashing.org Subject: Re: [PATCH 14/16] drivers/fsi: Add master unscan Message-ID: <20161207093124.GD14742@kroah.com> References: <1481069677-53660-1-git-send-email-christopher.lee.bostic@gmail.com> <1481069677-53660-15-git-send-email-christopher.lee.bostic@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1481069677-53660-15-git-send-email-christopher.lee.bostic@gmail.com> User-Agent: Mutt/1.7.2 (2016-11-26) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3912 Lines: 136 On Tue, Dec 06, 2016 at 06:14:35PM -0600, Chris Bostic wrote: > From: Chris Bostic > > Allow a master to undo a previous scan. Should a master scan a bus > twice it will need to ensure it doesn't double register any > previously detected device. > > Signed-off-by: Chris Bostic > --- > drivers/fsi/fsi-core.c | 36 +++++++++++++++++++++++++++++++++++- > drivers/fsi/fsi-master.h | 2 ++ > include/linux/fsi.h | 1 + > 3 files changed, 38 insertions(+), 1 deletion(-) > > diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c > index a28434b..8ccfe50 100644 > --- a/drivers/fsi/fsi-core.c > +++ b/drivers/fsi/fsi-core.c > @@ -41,6 +41,8 @@ > static atomic_t master_idx = ATOMIC_INIT(-1); > > struct fsi_slave { > + struct list_head list_link; /* Master's list of slaves */ > + struct list_head my_engines; > struct device dev; > struct fsi_master *master; > int link; > @@ -196,6 +198,8 @@ static int fsi_slave_scan(struct fsi_slave *slave) > uint32_t conf; > int rc, i; > > + INIT_LIST_HEAD(&slave->my_engines); > + > /* > * scan engines > * > @@ -264,7 +268,9 @@ static int fsi_slave_scan(struct fsi_slave *slave) > if (rc) { > dev_warn(&slave->dev, "add failed: %d\n", rc); > put_device(&dev->dev); > + continue; > } > + list_add(&dev->link, &slave->my_engines); > } > > engine_addr += slots * engine_page_size; > @@ -357,7 +363,7 @@ static int fsi_slave_init(struct fsi_master *master, > put_device(&slave->dev); > return rc; > } > - > + list_add(&slave->list_link, &master->my_slaves); > fsi_slave_scan(slave); > return 0; > } > @@ -388,6 +394,11 @@ static int fsi_master_scan(struct fsi_master *master) > int link, slave_id, rc; > uint32_t smode; > > + if (!master->slave_list) { > + INIT_LIST_HEAD(&master->my_slaves); > + master->slave_list = true; > + } > + > for (link = 0; link < master->n_links; link++) { > rc = fsi_master_link_enable(master, link); > if (rc) { > @@ -423,9 +434,31 @@ static int fsi_master_scan(struct fsi_master *master) > return 0; > } > > +static void fsi_master_unscan(struct fsi_master *master) > +{ > + struct fsi_slave *slave, *slave_tmp; > + struct fsi_device *fsi_dev, *fsi_dev_tmp; > + > + if (!master->slave_list) > + return; > + > + list_for_each_entry_safe(slave, slave_tmp, &master->my_slaves, > + list_link) { > + list_del(&slave->list_link); > + list_for_each_entry_safe(fsi_dev, fsi_dev_tmp, > + &slave->my_engines, link) { > + list_del(&fsi_dev->link); > + put_device(&fsi_dev->dev); > + } > + device_unregister(&slave->dev); > + } > + master->slave_list = false; > +} > + > int fsi_master_register(struct fsi_master *master) > { > master->idx = atomic_inc_return(&master_idx); > + master->slave_list = false; > get_device(master->dev); > fsi_master_scan(master); > return 0; > @@ -434,6 +467,7 @@ int fsi_master_register(struct fsi_master *master) > > void fsi_master_unregister(struct fsi_master *master) > { > + fsi_master_unscan(master); > put_device(master->dev); > } > EXPORT_SYMBOL_GPL(fsi_master_unregister); > diff --git a/drivers/fsi/fsi-master.h b/drivers/fsi/fsi-master.h > index 56aad0e..454af2b 100644 > --- a/drivers/fsi/fsi-master.h > +++ b/drivers/fsi/fsi-master.h > @@ -20,6 +20,8 @@ > #include > > struct fsi_master { > + struct list_head my_slaves; > + bool slave_list; > struct device *dev; > int idx; > int n_links; > diff --git a/include/linux/fsi.h b/include/linux/fsi.h > index 66bce48..924502b 100644 > --- a/include/linux/fsi.h > +++ b/include/linux/fsi.h > @@ -18,6 +18,7 @@ > #include > > struct fsi_device { > + struct list_head link; /* for slave's list */ Can't you use the device list on the bus instead? Putting a device on multiple lists gets tricky very quickly :( thanks, greg k-h