Re: [PATCH v3 3/7] USB: EHCI: make ehci-s5p a separate driver

From: Alan Stern
Date: Fri Mar 29 2013 - 15:41:46 EST


On Thu, 28 Mar 2013, Arnd Bergmann wrote:

> From: Manjunath Goudar <manjunath.goudar@xxxxxxxxxx>
>
> Separate the Samsung S5P/EXYNOS host controller driver from ehci-hcd
> host code so that it can be built as a separate driver module.
> This work is part of enabling multi-platform kernels on ARM;
> however, note that other changes are still needed before S5P/EXYNOS can
> be booted with a multi-platform kernel. We currently expect those
> to get merged for 3.10.
>
> With the infrastructure added by Alan Stern in patch 3e0232039
> "USB: EHCI: prepare to make ehci-hcd a library module", we can
> avoid this problem by turning a bus glue into a separate
> module, as we do here for the s5p bus glue.
>
> In V3:
> -Detail commit message added here,why this patch is required.
> -MODULE_LICENSE is GPL v2.
> -Added .extra_priv_size to eliminate the separate allocation of the s5p_ehci_hcd structure
> and removed .reset function pointer initialization.
> -Arranged #include's in alphabetical order.
> -After using extra_priv_size initialization,struct usb_hcd *hcd is redundant that's why removed
> from the prob function.
> -Eliminated s5p_ehci_phy_enable,contents of statements moved into the s5p_ehci_probe
> -Eliminated s5p_ehci_phy_disable, contents of statements moved into the s5p_ehci_remove.

And several other places as well.

Personally, I would have left these two functions the way they were and
relied on the compiler to inline them when appropriate. Eliminating
them just makes the code more complicated.

...

> @@ -113,9 +76,10 @@ static u64 ehci_s5p_dma_mask = DMA_BIT_MASK(32);
>
> static int s5p_ehci_probe(struct platform_device *pdev)
> {
> + struct usb_hcd *hcd ;
> struct s5p_ehci_platdata *pdata = pdev->dev.platform_data;
> + const struct hc_driver *driver = &s5p_ehci_hc_driver;
> struct s5p_ehci_hcd *s5p_ehci;
> - struct usb_hcd *hcd;

What's the reason for these changes? There's no need for the "driver"
variable, and improper whitespace was added to the declaration of
"hcd".

> @@ -153,16 +117,12 @@ static int s5p_ehci_probe(struct platform_device *pdev)
> s5p_ehci->otg = phy->otg;
> }
>
> - s5p_ehci->dev = &pdev->dev;
> -
> - hcd = usb_create_hcd(&s5p_ehci_hc_driver, &pdev->dev,
> - dev_name(&pdev->dev));
> + hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));

s5p_ehci is not initialized correctly. The devm_kzalloc() call was
left in and to_s5p_ehci() was not called. Was anybody able to test
this patch?

Alan Stern

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