On Tue, 2014-03-25 at 18:44 +0800, rogera...@realtek.com wrote:
> From: Roger Tseng <rogera...@realtek.com>

> +static int rtsx_usb_bulk_transfer_sglist(struct rtsx_ucr *ucr,
> +             unsigned int pipe, struct scatterlist *sg, int num_sg,
> +             unsigned int length, unsigned int *act_len, int timeout)
> +{
> +     int ret;
> +
> +     dev_dbg(&ucr->pusb_intf->dev, "%s: xfer %u bytes, %d entries\n",
> +                     __func__, length, num_sg);
> +     ret = usb_sg_init(&ucr->current_sg, ucr->pusb_dev, pipe, 0,
> +                     sg, num_sg, length, GFP_NOIO);
> +     if (ret)
> +             return ret;
> +
> +     ucr->sg_timer.expires = jiffies + msecs_to_jiffies(timeout);
> +     add_timer(&ucr->sg_timer);
> +     usb_sg_wait(&ucr->current_sg);
> +     del_timer(&ucr->sg_timer);
> +

A slight race. You cannot rule out that the timer handler is still
running when you call this the next time. You'd better use
del_timer_sync()

> +static int rtsx_usb_probe(struct usb_interface *intf,
> +                      const struct usb_device_id *id)
> +{
> +     struct usb_device *usb_dev = interface_to_usbdev(intf);
> +     struct rtsx_ucr *ucr;
> +     int ret;
> +
> +     dev_dbg(&intf->dev,
> +             ": Realtek USB Card Reader found at bus %03d address %03d\n",
> +              usb_dev->bus->busnum, usb_dev->devnum);
> +
> +     ucr = devm_kzalloc(&intf->dev, sizeof(*ucr), GFP_KERNEL);
> +     if (!ucr)
> +             return -ENOMEM;
> +
> +     ucr->pusb_dev = usb_dev;
> +
> +     ucr->iobuf = usb_alloc_coherent(ucr->pusb_dev, IOBUF_SIZE,
> +                     GFP_KERNEL, &ucr->iobuf_dma);
> +     if (!ucr->iobuf)
> +             return -ENOMEM;
> +
> +     usb_set_intfdata(intf, ucr);
> +
> +     ucr->vendor_id = id->idVendor;
> +     ucr->product_id = id->idProduct;
> +     ucr->cmd_buf = ucr->rsp_buf = ucr->iobuf;
> +
> +     mutex_init(&ucr->dev_mutex);
> +
> +     ucr->pusb_intf = intf;
> +
> +     /* initialize */
> +     ret = rtsx_usb_init_chip(ucr);
> +     if (ret)
> +             goto out_init_fail;
> +
> +     ret = mfd_add_devices(&intf->dev, usb_dev->devnum, rtsx_usb_cells,
> +                     ARRAY_SIZE(rtsx_usb_cells), NULL, 0, NULL);

Race condition. What prevents the mfd layer from using this device
before you've finished the next steps of the initialisation?

> +     if (ret)
> +             goto out_init_fail;
> +
> +     /* initialize USB SG transfer timer */
> +     init_timer(&ucr->sg_timer);
> +     setup_timer(&ucr->sg_timer, rtsx_usb_sg_timed_out, (unsigned long) ucr);
> +#ifdef CONFIG_PM
> +     intf->needs_remote_wakeup = 1;

Why?
> +     usb_enable_autosuspend(usb_dev);
> +#endif
> +
> +     return 0;
> +
> +out_init_fail:
> +     usb_free_coherent(ucr->pusb_dev, IOBUF_SIZE, ucr->iobuf,
> +                     ucr->iobuf_dma);
> +     return ret;
> +}
> +
> +static void rtsx_usb_disconnect(struct usb_interface *intf)
> +{
> +     struct rtsx_ucr *ucr = (struct rtsx_ucr *)usb_get_intfdata(intf);
> +
> +     dev_dbg(&intf->dev, "%s called\n", __func__);
> +
> +     mfd_remove_devices(&intf->dev);
> +
> +     usb_set_intfdata(ucr->pusb_intf, NULL);
> +     usb_free_coherent(ucr->pusb_dev, IOBUF_SIZE, ucr->iobuf,
> +                     ucr->iobuf_dma);
> +}
> +
> +#ifdef CONFIG_PM
> +static int rtsx_usb_suspend(struct usb_interface *intf, pm_message_t message)
> +{
> +     struct rtsx_ucr *ucr =
> +             (struct rtsx_ucr *)usb_get_intfdata(intf);
> +
> +     dev_dbg(&intf->dev, "%s called with pm message 0x%04u\n",
> +                     __func__, message.event);
> +
> +     mutex_lock(&ucr->dev_mutex);
> +     rtsx_usb_turn_off_led(ucr);

When is this turned on again?

> +     mutex_unlock(&ucr->dev_mutex);
> +     return 0;
> +}
> +
> +static int rtsx_usb_resume(struct usb_interface *intf)
> +{
> +     return 0;
> +}
> +
> +static int rtsx_usb_reset_resume(struct usb_interface *intf)
> +{
> +     struct rtsx_ucr *ucr =
> +             (struct rtsx_ucr *)usb_get_intfdata(intf);
> +
> +     rtsx_usb_reset_chip(ucr);
> +     return 0;
> +}
> +
> +#else /* CONFIG_PM */
> +
> +#define rtsx_usb_suspend NULL
> +#define rtsx_usb_resume NULL
> +#define rtsx_usb_reset_resume NULL
> +
> +#endif /* CONFIG_PM */
> +
> +
> +static int rtsx_usb_pre_reset(struct usb_interface *intf)
> +{
> +     struct rtsx_ucr *ucr = (struct rtsx_ucr *)usb_get_intfdata(intf);
> +
> +     mutex_lock(&ucr->dev_mutex);
> +     return 0;
> +}
> +
> +static int rtsx_usb_post_reset(struct usb_interface *intf)
> +{
> +     struct rtsx_ucr *ucr = (struct rtsx_ucr *)usb_get_intfdata(intf);
> +
> +     mutex_unlock(&ucr->dev_mutex);
> +     return 0;
> +}
> +
> +static struct usb_device_id rtsx_usb_usb_ids[] = {
> +     { USB_DEVICE(0x0BDA, 0x0129) },
> +     { USB_DEVICE(0x0BDA, 0x0139) },
> +     { USB_DEVICE(0x0BDA, 0x0140) },
> +     { }
> +};
> +
> +static struct usb_driver rtsx_usb_driver = {
> +     .name                   = "rtsx_usb",
> +     .probe                  = rtsx_usb_probe,
> +     .disconnect             = rtsx_usb_disconnect,
> +     .suspend                = rtsx_usb_suspend,
> +     .resume                 = rtsx_usb_resume,
> +     .reset_resume           = rtsx_usb_reset_resume,
> +     .pre_reset              = rtsx_usb_pre_reset,
> +     .post_reset             = rtsx_usb_post_reset,
> +     .id_table               = rtsx_usb_usb_ids,
> +     .supports_autosuspend   = 1,
> +     .soft_unbind            = 1,
> +};
> +

        Regards
                Oliver


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