Re: [PATCH RFT 2/2] macb: kill PHY reset code

From: Nicolas Ferre
Date: Tue Apr 12 2016 - 10:45:20 EST


Le 12/04/2016 15:40, Andrew Lunn a écrit :
> On Tue, Apr 12, 2016 at 11:22:10AM +0200, Nicolas Ferre wrote:
>> Le 11/04/2016 04:28, Andrew Lunn a écrit :
>>> On Sat, Apr 09, 2016 at 01:25:03AM +0300, Sergei Shtylyov wrote:
>>>> With the 'phylib' now being aware of the "reset-gpios" PHY node property,
>>>> there should be no need to frob the PHY reset in this driver anymore...
>>>>
>>>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
>>>>
>>>> ---
>>>> drivers/net/ethernet/cadence/macb.c | 17 -----------------
>>>> drivers/net/ethernet/cadence/macb.h | 1 -
>>>> 2 files changed, 18 deletions(-)
>>>>
>>>> Index: net-next/drivers/net/ethernet/cadence/macb.c
>>>> ===================================================================
>>>> --- net-next.orig/drivers/net/ethernet/cadence/macb.c
>>>> +++ net-next/drivers/net/ethernet/cadence/macb.c
>>>> @@ -2884,7 +2884,6 @@ static int macb_probe(struct platform_de
>>>> = macb_clk_init;
>>>> int (*init)(struct platform_device *) = macb_init;
>>>> struct device_node *np = pdev->dev.of_node;
>>>> - struct device_node *phy_node;
>>>> const struct macb_config *macb_config = NULL;
>>>> struct clk *pclk, *hclk = NULL, *tx_clk = NULL;
>>>> unsigned int queue_mask, num_queues;
>>>> @@ -2977,18 +2976,6 @@ static int macb_probe(struct platform_de
>>>> else
>>>> macb_get_hwaddr(bp);
>>>>
>>>> - /* Power up the PHY if there is a GPIO reset */
>>>> - phy_node = of_get_next_available_child(np, NULL);
>>>> - if (phy_node) {
>>>> - int gpio = of_get_named_gpio(phy_node, "reset-gpios", 0);
>>>> -
>>>> - if (gpio_is_valid(gpio)) {
>>>> - bp->reset_gpio = gpio_to_desc(gpio);
>>>> - gpiod_direction_output(bp->reset_gpio, 1);
>>>
>>> Hi Sergei
>>>
>>> The code you are deleting would of ignored the flags in the gpio
>> I don't parse this.
>>
>> The code deleted does take the flag into account. And the DT property
>> associated to it seems correct to me (I mean, with proper flag
>> specification).
>
> Hi Nicolas
>
> of_get_named_gpio() does not do anything with the flags. So for
> example,
>
> gpios = <&gpio0 12 GPIO_ACTIVE_LOW>;
>
> the GPIO_ACTIVE_LOW would be ignored. If you want the flags to be
> respected, you need to use the gpiod API for all calls, in particular,
> you need to use something which calls gpiod_get_index(), since that is
> the only function to call gpiod_parse_flags() to translate
> GPIO_ACTIVE_LOW into a flag within the gpio descriptor.

Ok, I remember what confused me now: this code, used to be something around:
devm_gpiod_get_optional(&bp->pdev->dev, "phy-reset", GPIOD_OUT_HIGH);
before it has been changed to the chunk above... So, yes, the DT flag
was not handled anyway...

Sorry for the noise and thanks for the clarification.

Bye,
--
Nicolas Ferre