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From: kishon@ti•com (Kishon Vijay Abraham I)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 01/15] drivers: phy: add generic PHY framework
Date: Fri, 19 Jul 2013 11:07:10 +0530	[thread overview]
Message-ID: <51E8D086.809@ti.com> (raw)
In-Reply-To: <20130718154954.GA31961@kroah.com>

Hi,

On Thursday 18 July 2013 09:19 PM, Greg KH wrote:
> On Thu, Jul 18, 2013 at 02:29:52PM +0530, Kishon Vijay Abraham I wrote:
>> Hi,
>>
>> On Thursday 18 July 2013 12:50 PM, Greg KH wrote:
>>> On Thu, Jul 18, 2013 at 12:16:10PM +0530, Kishon Vijay Abraham I wrote:
>>>> +struct phy_provider *__of_phy_provider_register(struct device *dev,
>>>> +	struct module *owner, struct phy * (*of_xlate)(struct device *dev,
>>>> +	struct of_phandle_args *args));
>>>> +struct phy_provider *__devm_of_phy_provider_register(struct device *dev,
>>>> +	struct module *owner, struct phy * (*of_xlate)(struct device *dev,
>>>> +	struct of_phandle_args *args))
>>>> +
>>>> +__of_phy_provider_register and __devm_of_phy_provider_register can be used to
>>>> +register the phy_provider and it takes device, owner and of_xlate as
>>>> +arguments. For the dt boot case, all PHY providers should use one of the above
>>>> +2 APIs to register the PHY provider.
>>>
>>> Why do you have __ for the prefix of a public function?  Is that really
>>> the way that OF handles this type of thing?
>>
>> I have a macro of_phy_provider_register/devm_of_phy_provider_register that
>> calls these functions and should be used by the PHY drivers. Probably I should
>> make a mention of it in the Documentation.
> 
> Yes, mention those as you never want to be calling __* functions
> directly, right?

correct.
> 
>>>> +	ret = dev_set_name(&phy->dev, "%s.%d", dev_name(dev), id);
>>>
>>> Your naming is odd, no "phy" anywhere in it?  You rely on the sender to
>>> never send a duplicate name.id pair?  Why not create your own ids based
>>> on the number of phys in the system, like almost all other classes and
>>> subsystems do?
>>
>> hmm.. some PHY drivers use the id they provide to perform some of their
>> internal operation as in [1] (This is used only if a single PHY provider
>> implements multiple PHYS). Probably I'll add an option like PLATFORM_DEVID_AUTO
>> to give the PHY drivers an option to use auto id.
>>
>> [1] ->
>> http://archive.arm.linux.org.uk/lurker/message/20130628.134308.4a8f7668.ca.html
> 
> No, who cares about the id?  No one outside of the phy core ever should,
> because you pass back the only pointer that they really do care about,
> if they need to do anything with the device.  Use that, and then you can

hmm.. ok.

> rip out all of the "search for a phy by a string" logic, as that's not

Actually this is needed for non-dt boot case. In the case of dt boot, we use a
phandle by which the controller can get a reference to the phy. But in the case
of non-dt boot, the controller can get a reference to the phy only by label.
> needed either.  Just stick to the pointer, it's easier, and safer that
> way.
> 
>>>> +static inline int phy_pm_runtime_get(struct phy *phy)
>>>> +{
>>>> +	if (WARN(IS_ERR(phy), "Invalid PHY reference\n"))
>>>> +		return -EINVAL;
>>>
>>> Why would phy ever not be valid and a error pointer?  And why dump the
>>> stack if that happens, that seems really extreme.
>>
>> hmm.. there might be cases where the same controller in one soc needs PHY
>> control and in some other soc does not need PHY control. In such cases, we
>> might get error pointer here.
>> I'll change WARN to dev_err.
> 
> I still don't understand.  You have control over the code that calls
> these functions, just ensure that they pass in a valid pointer, it's
> that simple.  Or am I missing something?

You are right. Valid pointer check can be done in controller code as well.

Thanks
Kishon

  reply	other threads:[~2013-07-19  5:37 UTC|newest]

Thread overview: 99+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-18  6:46 [PATCH 00/15] PHY framework Kishon Vijay Abraham I
2013-07-18  6:46 ` [PATCH 01/15] drivers: phy: add generic " Kishon Vijay Abraham I
2013-07-18  7:20   ` Greg KH
2013-07-18  8:59     ` Kishon Vijay Abraham I
2013-07-18 15:49       ` Greg KH
2013-07-19  5:37         ` Kishon Vijay Abraham I [this message]
2013-07-19  5:43           ` Greg KH
2013-07-19  5:55             ` Kishon Vijay Abraham I
2013-07-19  6:29               ` Greg KH
2013-07-19  6:36                 ` Kishon Vijay Abraham I
2013-07-19 15:54                   ` Stephen Warren
2013-07-20  3:15                     ` Kishon Vijay Abraham I
2013-07-19 23:50                   ` Greg KH
2013-07-20  3:19                     ` Kishon Vijay Abraham I
2013-07-20 22:00                       ` Greg KH
2013-07-21  2:32                         ` Alan Stern
2013-07-21  2:59                           ` Greg KH
2013-07-21 10:22                             ` Sascha Hauer
2013-07-21 15:48                               ` Greg KH
2013-07-21 17:14                                 ` Sylwester Nawrocki
2013-07-21 19:22                                   ` Alan Stern
2013-07-22  7:25                                     ` Kishon Vijay Abraham I
2013-07-22 14:44                                       ` Alan Stern
2013-07-23  5:47                                         ` Kishon Vijay Abraham I
2013-07-23  7:29                                         ` Tomasz Figa
2013-07-23  7:55                                           ` Tomasz Figa
2013-07-23 14:37                                             ` Alan Stern
2013-07-23 14:50                                               ` Tomasz Figa
2013-07-23 15:18                                               ` Kishon Vijay Abraham I
2013-07-23 16:18                                                 ` Greg KH
2013-07-23 16:28                                                   ` Kishon Vijay Abraham I
2013-07-23 16:35                                                     ` Greg KH
2013-07-23 16:50                                                   ` Tomasz Figa
2013-07-23 17:37                                                     ` Greg KH
2013-07-23 17:44                                                       ` Mark Brown
2013-07-23 18:01                                                         ` Greg KH
2013-07-23 19:31                                                           ` Mark Brown
2013-07-23 19:44                                                             ` Greg KH
2013-07-23 20:07                                                               ` Tomasz Figa
2013-07-23 20:50                                                                 ` Greg KH
2013-07-23 21:05                                                                   ` Tomasz Figa
2013-07-23 21:23                                                                     ` Greg KH
2013-07-23 23:48                                                               ` Mark Brown
2013-07-23 17:48                                                       ` Tomasz Figa
2013-07-23 18:04                                                         ` Greg KH
2013-07-23 20:46                                                           ` Tomasz Figa
2013-07-23 19:36                                                     ` Alan Stern
2013-07-23 20:20                                                       ` Tomasz Figa
2013-07-23 20:53                                                         ` Alan Stern
2013-07-23 21:02                                                           ` Tomasz Figa
2013-07-23 21:14                                                             ` Alan Stern
2013-07-23 21:31                                                               ` Tomasz Figa
2013-07-24 18:32                                                                 ` Arnd Bergmann
2013-07-25  5:11                                                                   ` Kishon Vijay Abraham I
2013-07-25  7:54                                                                     ` Arnd Bergmann
2013-07-25  9:29                                                                   ` Sylwester Nawrocki
2013-07-25  9:29                                                                   ` Mark Brown
2013-07-25 10:11                                                                     ` Kishon Vijay Abraham I
2013-07-25 10:16                                                                   ` Laurent Pinchart
2013-07-25 10:26                                                                     ` Florian Fainelli
2013-07-25 11:00                                                                     ` Arnd Bergmann
2013-07-25 11:10                                                                       ` Laurent Pinchart
2013-07-25 12:09                                                                       ` Mark Brown
2013-07-23 17:34                                               ` Mark Brown
2013-07-22 15:04                                       ` Greg KH
2013-07-23  5:34                                         ` Kishon Vijay Abraham I
2013-07-21 10:31                             ` Tomasz Figa
2013-07-21 11:07                               ` Kishon Vijay Abraham I
2013-07-21 11:12                                 ` Tomasz Figa
2013-07-21 15:46                                   ` Greg KH
2013-07-30  7:11                                     ` Felipe Balbi
2013-07-31  5:44                                       ` Kishon Vijay Abraham I
2013-07-31  6:15                                         ` Felipe Balbi
2013-08-13 10:44                                           ` Kishon Vijay Abraham I
2013-08-13 11:37                                             ` Tomasz Figa
2013-08-13 12:05                                               ` Kishon Vijay Abraham I
2013-08-13 22:19                                                 ` Sylwester Nawrocki
2013-08-13 23:04                                                   ` Tomasz Figa
2013-08-14 15:05                                                     ` Kishon Vijay Abraham I
2013-08-19  5:28                                                       ` Kishon Vijay Abraham I
2013-08-20 12:26                                                         ` Felipe Balbi
2013-07-18  6:46 ` [PATCH 02/15] usb: phy: omap-usb2: use the new " Kishon Vijay Abraham I
2013-07-18  7:21   ` Greg KH
2013-07-18  9:00     ` Kishon Vijay Abraham I
2013-07-18  6:46 ` [PATCH 03/15] usb: phy: twl4030: " Kishon Vijay Abraham I
2013-07-18  6:46 ` [PATCH 04/15] ARM: OMAP: USB: Add phy binding information Kishon Vijay Abraham I
2013-07-18  7:02   ` Tony Lindgren
2013-07-18  6:46 ` [PATCH 05/15] ARM: dts: omap: update usb_otg_hs data Kishon Vijay Abraham I
2013-07-18  7:05   ` Tony Lindgren
2013-07-18  6:46 ` [PATCH 06/15] usb: musb: omap2430: use the new generic PHY framework Kishon Vijay Abraham I
2013-07-18  6:46 ` [PATCH 07/15] usb: phy: omap-usb2: remove *set_suspend* callback from omap-usb2 Kishon Vijay Abraham I
2013-07-18  6:46 ` [PATCH 08/15] usb: phy: twl4030-usb: remove *set_suspend* and *phy_init* ops Kishon Vijay Abraham I
2013-07-18  6:46 ` [PATCH 09/15] phy: Add driver for Exynos MIPI CSIS/DSIM DPHYs Kishon Vijay Abraham I
2013-07-18  6:46 ` [PATCH 10/15] video: exynos_mipi_dsim: Use the generic PHY driver Kishon Vijay Abraham I
2013-07-18  6:46 ` [PATCH 11/15] exynos4-is: Use the generic MIPI CSIS " Kishon Vijay Abraham I
2013-07-18  6:46 ` [PATCH 12/15] ARM: Samsung: Remove the MIPI PHY setup code Kishon Vijay Abraham I
2013-07-18  6:46 ` [PATCH 13/15] phy: Add driver for Exynos DP PHY Kishon Vijay Abraham I
2013-07-18  6:46 ` [PATCH 14/15] video: exynos_dp: remove non-DT support for Exynos Display Port Kishon Vijay Abraham I
2013-07-18  6:46 ` [PATCH 15/15] video: exynos_dp: Use the generic PHY driver Kishon Vijay Abraham I

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