From: Florian Fainelli <f.fainelli@gmail.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: netdev@vger.kernel.org, Jason Cooper <jason@lakedaemon.net>,
Andrew Lunn <andrew@lunn.ch>,
Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
Gregory Clement <gregory.clement@free-electrons.com>,
Russell King <linux@armlinux.org.uk>,
Vivien Didelot <vivien.didelot@savoirfairelinux.com>,
"David S. Miller" <davem@davemloft.net>,
"moderated list:ARM SUB-ARCHITECTURES"
<linux-arm-kernel@lists.infradead.org>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH net-next v3 05/10] drivers: base: Add device_find_class()
Date: Sun, 15 Jan 2017 09:39:01 -0800 [thread overview]
Message-ID: <2fcdb4a5-621b-1691-e4ba-2dffe1186fe0@gmail.com> (raw)
In-Reply-To: <20170115110455.GE26374@kroah.com>
On 01/15/2017 03:04 AM, Greg KH wrote:
> On Sat, Jan 14, 2017 at 01:47:08PM -0800, Florian Fainelli wrote:
>> Add a helper function to lookup a device reference given a class name.
>> This is a preliminary patch to remove adhoc code from net/dsa/dsa.c and
>> make it more generic.
>>
>> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
>> ---
>> drivers/base/core.c | 19 +++++++++++++++++++
>> include/linux/device.h | 1 +
>> 2 files changed, 20 insertions(+)
>>
>> diff --git a/drivers/base/core.c b/drivers/base/core.c
>> index 020ea7f05520..3dd6047c10d8 100644
>> --- a/drivers/base/core.c
>> +++ b/drivers/base/core.c
>> @@ -2065,6 +2065,25 @@ struct device *device_find_child(struct device *parent, void *data,
>> }
>> EXPORT_SYMBOL_GPL(device_find_child);
>>
>> +static int dev_is_class(struct device *dev, void *class)
>> +{
>> + if (dev->class != NULL && !strcmp(dev->class->name, class))
>> + return 1;
>> +
>> + return 0;
>> +}
>> +
>> +struct device *device_find_class(struct device *parent, char *class)
>
> Why are you using the char * for a class, and not just a pointer to
> "struct class"? That seems to be the most logical one, no need to rely
> on string comparisons here.
A more reflective name of what that does would probably be
device_find_by_class_name() or something alike.
>
> Also, what is this being used for? You aren't trying to walk up the
> device heirachy to find a specific "type" of device, are you? If so,
> ugh, I ranted about this in the past when the hyperv driver was trying
> to do such a thing...
What's a better way to do that though?
>
>> +{
>> + if (dev_is_class(parent, class)) {
>> + get_device(parent);
>> + return parent;
>> + }
>> +
>> + return device_find_child(parent, class, dev_is_class);
>
> You are trying to find a peer device with the same parent that belongs
> to a specific class?
Correct, network devices, and MDIO bus devices usually (always?) set
dev.parent.
>
> Again, what is this being used for?
See my other replies in patches 6, 7 and how it is used in patches 8 and
10 for instance.
>
> And all exported driver core functions should have full kerneldoc
> information for them so that people know how to use them, and what the
> constraints are (see device_find_child() as an example.) Please do that
> here as well because you are returning a pointer to a structure with the
> reference count incremented, callers need to know that.
Sure.
--
Florian
next prev parent reply other threads:[~2017-01-15 17:39 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-14 21:47 [PATCH net-next v3 00/10] net: dsa: Support for pdata in dsa2 Florian Fainelli
2017-01-14 21:47 ` [PATCH net-next v3 01/10] net: dsa: Pass device pointer to dsa_register_switch Florian Fainelli
2017-01-14 21:47 ` [PATCH net-next v3 02/10] net: dsa: Make most functions take a dsa_port argument Florian Fainelli
2017-01-14 21:47 ` [PATCH net-next v3 03/10] net: dsa: Suffix function manipulating device_node with _dn Florian Fainelli
2017-01-14 21:47 ` [PATCH net-next v3 04/10] net: dsa: Move ports assignment closer to error checking Florian Fainelli
2017-01-15 10:17 ` Sergei Shtylyov
2017-01-14 21:47 ` [PATCH net-next v3 05/10] drivers: base: Add device_find_class() Florian Fainelli
2017-01-15 11:04 ` Greg KH
2017-01-15 17:39 ` Florian Fainelli [this message]
2017-01-14 21:47 ` [PATCH net-next v3 06/10] net: dsa: Migrate to device_find_class() Florian Fainelli
2017-01-15 11:06 ` Greg KH
2017-01-15 17:27 ` Florian Fainelli
2017-01-15 17:39 ` Greg KH
2017-01-15 17:52 ` Florian Fainelli
2017-01-15 19:16 ` Andrew Lunn
2017-01-16 20:01 ` Florian Fainelli
2017-01-18 7:06 ` Greg KH
2017-01-19 14:28 ` Greg KH
2017-01-19 14:53 ` Andrew Lunn
2017-01-19 16:30 ` Greg KH
2017-01-19 16:35 ` Russell King - ARM Linux
2017-01-19 16:51 ` Russell King - ARM Linux
2017-01-19 18:12 ` Florian Fainelli
2017-01-24 18:59 ` Florian Fainelli
2017-01-25 21:25 ` Greg KH
2017-01-30 22:46 ` Florian Fainelli
2017-02-10 13:02 ` Greg KH
2017-02-10 18:30 ` Florian Fainelli
2017-02-12 12:56 ` Greg KH
2017-01-14 21:47 ` [PATCH net-next v3 07/10] net: Relocate dev_to_net_device() into core Florian Fainelli
2017-01-15 11:07 ` Greg KH
2017-01-15 17:20 ` Florian Fainelli
2017-01-15 17:40 ` Greg KH
2017-01-14 21:47 ` [PATCH net-next v3 08/10] net: dsa: Add support for platform data Florian Fainelli
2017-01-14 21:47 ` [PATCH net-next v3 09/10] net: phy: Allow pre-declaration of MDIO devices Florian Fainelli
2017-01-14 21:47 ` [PATCH net-next v3 10/10] ARM: orion: Register DSA switch as a MDIO device Florian Fainelli
2017-01-15 11:08 ` [PATCH net-next v3 00/10] net: dsa: Support for pdata in dsa2 Greg KH
2017-01-15 17:40 ` Florian Fainelli
2017-01-15 17:49 ` Greg KH
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