On Tue, Jun 04, 2013 at 08:17:57PM +0800, 21cn...@gmail.com wrote:
> From: Rong Wang <rong.w...@csr.com>
>
> If global_phy is used when CONFIG_USB_PHY is not defined,
> usb_get_phy() returns ERR_PTR(-ENXIO). If we only check
> ci->transceiver is NULL or not in vbus_draw callback, it
> will return true and continue to dereference ERR_PTR(-ENXIO)
> which will cause a kernel panic.
If global_phy is used, the ci->transceiver should be NULL,
see below code at drivers/usb/chipidea/udc.c.
1799 if (ci->global_phy) {
1800 ci->transceiver = usb_get_phy(USB_PHY_TYPE_USB2);
1801 if (IS_ERR(ci->transceiver))
1802 ci->transceiver = NULL;
1803 }
>
> Tested on CSR SiRFatlasVI SoC platform which licensed chipidea.
>
> Signed-off-by: Rong Wang <rong.w...@csr.com>
> Signed-off-by: Barry Song <baohua.s...@csr.com>
> ---
> drivers/usb/chipidea/udc.c | 7 ++++---
> 1 files changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
> index 519ead2..822194b 100644
> --- a/drivers/usb/chipidea/udc.c
> +++ b/drivers/usb/chipidea/udc.c
> @@ -1392,7 +1392,7 @@ static int ci13xxx_vbus_draw(struct usb_gadget
> *_gadget, unsigned mA)
> {
> struct ci13xxx *ci = container_of(_gadget, struct ci13xxx, gadget);
>
> - if (ci->transceiver)
> + if (!IS_ERR_OR_NULL(ci->transceiver))
> return usb_phy_set_power(ci->transceiver, mA);
> return -ENOTSUPP;
> }
> @@ -1682,8 +1682,9 @@ static int udc_start(struct ci13xxx *ci)
> ci->transceiver = usb_get_phy(USB_PHY_TYPE_USB2);
>
> if (ci->platdata->flags & CI13XXX_REQUIRE_TRANSCEIVER) {
> - if (ci->transceiver == NULL) {
> - retval = -ENODEV;
> + if (IS_ERR_OR_NULL(ci->transceiver)) {
> + retval = ci->transceiver ?
> + PTR_ERR(ci->transceiver) : -ENODEV;
> goto destroy_eps;
> }
> }
> --
> 1.7.5.4
>
> --
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--
Best Regards,
Peter Chen
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