Re: [PATCH] USB: initialize or shutdown PHY when add or remove hostcontroller

From: Felipe Balbi
Date: Tue Jun 18 2013 - 04:03:44 EST


Hi,

On Tue, Jun 18, 2013 at 03:15:01AM -0400, Chao Xie wrote:
> Some controller need software to initialize PHY before add
> host controller, and shut down PHY after remove host controller.
> Add the generic code for these controllers so they do not need
> do it in its own host controller driver.
>
> Signed-off-by: Chao Xie <chao.xie@xxxxxxxxxxx>
> ---
> drivers/usb/core/hcd.c | 19 ++++++++++++++++++-
> 1 files changed, 18 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index d53547d..b26196b 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -43,6 +43,7 @@
>
> #include <linux/usb.h>
> #include <linux/usb/hcd.h>
> +#include <linux/usb/phy.h>
>
> #include "usb.h"
>
> @@ -2531,12 +2532,22 @@ int usb_add_hcd(struct usb_hcd *hcd,
> */
> set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
>
> + /* Initialize the PHY before other hardware operation. */
> + if (hcd->phy) {

this looks wrong for two reasons:

a) you're not grabbing the PHY here.

You can't just assume another entity grabbed your PHY for you.

b) usb_get_phy() returns an error number

so the proper check would be !IS_ERR()

--
balbi

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