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Subject: Re: [PATCH v2 4/7] net: phy: realtek: Enable accessing RTL8211E
 extension pages
To:     Matthias Kaehlcke <mka@chromium.org>
Cc:     "David S . Miller" <davem@davemloft.net>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Andrew Lunn <andrew@lunn.ch>,
        Florian Fainelli <f.fainelli@gmail.com>,
        netdev@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Douglas Anderson <dianders@chromium.org>
References: <20190703193724.246854-1-mka@chromium.org>
 <20190703193724.246854-4-mka@chromium.org>
 <dd7a569b-41e4-5925-88fc-227e69c82f67@gmail.com>
 <20190703203650.GF250418@google.com>
From:   Heiner Kallweit <hkallweit1@gmail.com>
Message-ID: <98326ec2-6e90-fd3a-32f5-cf0db26c31a9@gmail.com>
Date:   Wed, 3 Jul 2019 23:01:09 +0200
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On 03.07.2019 22:36, Matthias Kaehlcke wrote:
> On Wed, Jul 03, 2019 at 10:12:12PM +0200, Heiner Kallweit wrote:
>> On 03.07.2019 21:37, Matthias Kaehlcke wrote:
>>> The RTL8211E has extension pages, which can be accessed after
>>> selecting a page through a custom method. Add a function to
>>> modify bits in a register of an extension page and a helper for
>>> selecting an ext page.
>>>
>>> rtl8211e_modify_ext_paged() is inspired by its counterpart
>>> phy_modify_paged().
>>>
>>> Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
>>> ---
>>> Changes in v2:
>>> - assign .read/write_page handlers for RTL8211E
>>
>> Maybe this was planned, but it's not part of the patch.
> 
> Oops, it was definitely there when I tested ... I guess this got
> somehow lost when changing the patch order and resolving minor
> conflicts, seems like I only build tested after that :/
> 
RTL8211E also supports normal pages (reg 0x1f = page).
See e.g. rtl8168e_2_hw_phy_config in the r8169 driver, this network
chip has an integrated RTL8211E PHY. There settings on page 3 and 5
are done.
Therefore I would prefer to use .read/write_page for normal paging
in all Realtek PHY drivers. Means the code here would remain as it
is and just the changelog would need to be fixed.


>>> - use phy_select_page() and phy_restore_page(), get rid of
>>>   rtl8211e_restore_page()
>>> - s/rtl821e_select_ext_page/rtl8211e_select_ext_page/
>>> - updated commit message
>>> ---
>>>  drivers/net/phy/realtek.c | 42 +++++++++++++++++++++++++++++++++++++++
>>>  1 file changed, 42 insertions(+)
>>>
>>> diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c
>>> index eb815cbe1e72..9cd6241e2a6d 100644
>>> --- a/drivers/net/phy/realtek.c
>>> +++ b/drivers/net/phy/realtek.c
>>> @@ -27,6 +27,9 @@
>>>  #define RTL821x_EXT_PAGE_SELECT			0x1e
>>>  #define RTL821x_PAGE_SELECT			0x1f
>>>  
>>> +#define RTL8211E_EXT_PAGE			7
>>> +#define RTL8211E_EPAGSR				0x1e
>>> +
>>>  /* RTL8211E page 5 */
>>>  #define RTL8211E_EEE_LED_MODE1			0x05
>>>  #define RTL8211E_EEE_LED_MODE2			0x06
>>> @@ -58,6 +61,44 @@ static int rtl821x_write_page(struct phy_device *phydev, int page)
>>>  	return __phy_write(phydev, RTL821x_PAGE_SELECT, page);
>>>  }
>>>  
>>> +static int rtl8211e_select_ext_page(struct phy_device *phydev, int page)
>>> +{
>>> +	int ret, oldpage;
>>> +
>>> +	oldpage = phy_select_page(phydev, RTL8211E_EXT_PAGE);
>>> +	if (oldpage < 0)
>>> +		return oldpage;
>>> +
>>> +	ret = __phy_write(phydev, RTL8211E_EPAGSR, page);
>>> +	if (ret)
>>> +		return phy_restore_page(phydev, page, ret);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int __maybe_unused rtl8211e_modify_ext_paged(struct phy_device *phydev,
>>> +				    int page, u32 regnum, u16 mask, u16 set)
>>
>> This __maybe_unused isn't too nice as you use the function in a subsequent patch.
> 
> It's needed to avoid a compiler warning (unless we don't care about
> that for an interim version), the attribute is removed again in the
> next patch.
> 
OK