Re: [PATCH] USB: ehci-s5p: Fix phy reset

From: Alexander Graf
Date: Wed Mar 13 2013 - 20:30:24 EST

On 13.03.2013, at 18:59, Doug Anderson wrote:

> Alexander,
> On Wed, Mar 13, 2013 at 10:45 AM, Alexander Graf <agraf@xxxxxxx> wrote:
>>>> + gpio_free(gpio);
>>> Freeing the gpio is a little on the iffy side since you actually care
>>> about keeping the value. Perhaps you can change this to
>>> devm_gpio_request_one() and avoid the free? I was about to submit a
>>> patch to do just that (since otherwise you run into trouble if you
>>> ever defer the probe) but then ran across your patch.
>> I could also just return it when the function exits and only free it when we exit the probe function with a negative value. The reason I put it in here was that on probe deferral, the pin simply gets blocked.
>> However, I could probably also just completely take the gpio_free() out of this patch and resubmit, as it should be pretty much unrelated. Then you can patch it properly.
> Sure, if you want to resubmit without the gpio_free() I'll submit a
> new patch atop yours with the change to devm and people can see if
> they like it...

Hrm. So when I remove the gpio_free() again, I can't find the USB hub anymore. If I however postpone the whole reset procedure until after the potential deferral, it works (see patch below).

Any idea what is going on here?


diff --git a/drivers/usb/host/ehci-s5p.c b/drivers/usb/host/ehci-s5p.c
index f692f70..b29b2b8 100644
--- a/drivers/usb/host/ehci-s5p.c
+++ b/drivers/usb/host/ehci-s5p.c
@@ -136,8 +136,6 @@ static int s5p_ehci_probe(struct platform_device *pdev)
if (!pdev->dev.coherent_dma_mask)
pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);

- s5p_setup_vbus_gpio(pdev);
s5p_ehci = devm_kzalloc(&pdev->dev, sizeof(struct s5p_ehci_hcd),
if (!s5p_ehci)
@@ -157,6 +155,8 @@ static int s5p_ehci_probe(struct platform_device *pdev)
s5p_ehci->otg = phy->otg;

+ s5p_setup_vbus_gpio(pdev);
s5p_ehci->dev = &pdev->dev;

hcd = usb_create_hcd(&s5p_ehci_hc_driver, &pdev->dev,--
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