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

From: Roger Quadros
Date: Tue Jun 18 2013 - 04:27:52 EST


On 06/18/2013 11:01 AM, Felipe Balbi wrote:
> 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.

Isn't that done in the controller drivers e.g. ehci-fsl.c, ohci-omap, etc?
If the controllers don't want HCD core to manage the PHY they can just set it
to some error code.

cheers,
-roger
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