Enrico Mioso <mrkiko...@gmail.com> writes: > Hi guys! > It's my first experience, and util now I acquired a null pointer dereference, > which kicks my kernel off! :) > This is the patch ... I know for sure I'm doing something horrible! > I'm a newbie !! XD > > diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c > index 4709fa3..725d892 100644 > --- a/drivers/net/usb/cdc_ncm.c > +++ b/drivers/net/usb/cdc_ncm.c > @@ -52,7 +52,7 @@ > #include <linux/usb/usbnet.h> > #include <linux/usb/cdc.h> > #include <linux/usb/cdc_ncm.h> > - > +#include <linux/usb/cdc-wdm.h> > #define DRIVER_VERSION "14-Mar-2012" > > #if IS_ENABLED(CONFIG_USB_NET_CDC_MBIM) > @@ -62,12 +62,41 @@ static bool prefer_mbim; > #endif > module_param(prefer_mbim, bool, S_IRUGO | S_IWUSR); > MODULE_PARM_DESC(prefer_mbim, "Prefer MBIM setting on dual NCM/MBIM > functions"); > - > +atomic_t pmcount; > static void cdc_ncm_txpath_bh(unsigned long param); > static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx); > static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *hr_timer); > static struct usb_driver cdc_ncm_driver; > > +static int cdc_mbim_manage_power(struct usbnet *dev, int on) > +{ > + int rv = 0; > + > + > + if ((on && atomic_add_return(1, &pmcount) == 1) || (!on && > atomic_dec_and_test(&pmcount))) { > + /* need autopm_get/put here to ensure the usbcore sees the new > value */ > + rv = usb_autopm_get_interface(dev->intf); > + if (rv < 0) > + goto err; > + dev->intf->needs_remote_wakeup = on; > + usb_autopm_put_interface(dev->intf); > + } > +err: > + return rv; > +} > + > +static int cdc_mbim_wdm_manage_power(struct usb_interface *intf, int status) > +{ > + struct usbnet *dev = usb_get_intfdata(intf); > + > + /* can be called while disconnecting */ > + if (!dev) > + return 0; > + > + return cdc_mbim_manage_power(dev, status); > +} > + > +
For a simple test, I'd suggest ignoring PM for now. You can do usb_autopm_get_interface() on bind and a usb_autopm_put_interface() to make sure autosuspend doesn't complicate the testing. Just make a dummy manage_power function to make the subdriver registration happy. > static void > cdc_ncm_get_drvinfo(struct net_device *net, struct ethtool_drvinfo *info) > { > @@ -355,6 +384,7 @@ static const struct ethtool_ops cdc_ncm_ethtool_ops = { > int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 > data_altsetting) > { > struct cdc_ncm_ctx *ctx; > + struct usb_driver *subdriver; > struct usb_driver *driver; > u8 *buf; > int len; > @@ -507,6 +537,20 @@ advance: > dev->rx_urb_size = ctx->rx_max; > > ctx->tx_speed = ctx->rx_speed = 0; > + > + usb_driver_release_interface(driver, ctx->control); This does not make any sense to me... > + if (ctx->control == NULL){ > + printk("ctx->control is NULL!\n"); > + return -ENODEV; > + } > + if (&dev->status->desc == NULL){ > + printk("ctx->control is NULL!\n"); > + return -ENODEV; > + } > + subdriver = usb_cdc_wdm_register(ctx->control, > + &dev->status->desc, > + > le16_to_cpu(ctx->mbim_desc->wMaxControlMessage), > + cdc_mbim_wdm_manage_power); You cannot use ctx->mbim_desc here. It is NULL for any non MBIM device. Just use some static max message constant instead, like qmi_wwan does. We don't know how to guess the the correct value until we know what the protocol is. Bjørn -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html