Scsi - Index of

25
938 if (!us) {
939 printk(KERN_WARNING USB_STORAGE "Out of memory\n");
940 return -ENOMEM;
941 }
942 memset(us, 0, sizeof(struct us_data));
首先先贴出这么几行,两个参数不用多说了,struct usb_interface 和struct usb_device_id 的
这两个指针都是前面介绍过的,来自usb core 那一层,我们整个故事里用到的就是这么一个,不是
说一会指向你,一会指向他,这两个指针的指向是定下来的.
930 行,最重要的一个数据结构终于在这种神不知鬼不觉的地方惊艳亮相了.整个usb-storage
模块里边自己定义的数据结构不多,但是us_data 算一个.这个数据结构是跟随我们的代码一直
走下去的,如影随形,几乎处处都可以看见她的身影.先把它的代码贴出来,来自
drivers/usb/storage/usb.h:
105 /* we allocate one of these for every device that we remember */
106 struct us_data {
107 /* The device we're working with
108 * It's important to note:
109 * (o) you must hold dev_semaphore to change pusb_dev
110 */
111 struct semaphore dev_semaphore; /* protect pusb_dev */
112 struct usb_device *pusb_dev; /* this usb_device */
113 struct usb_interface *pusb_intf; /* this interface */
114 struct us_unusual_dev *unusual_dev; /* device-filter entry */
115 unsigned long flags; /* from filter initially */
116 unsigned int send_bulk_pipe; /* cached pipe values */
117 unsigned int recv_bulk_pipe;
118 unsigned int send_ctrl_pipe;
119 unsigned int recv_ctrl_pipe;
120 unsigned int recv_intr_pipe;
121
122 /* information about the device */
123 char vendor[USB_STOR_STRING_LEN];
124 char product[USB_STOR_STRING_LEN];
125 char serial[USB_STOR_STRING_LEN];
126 char *transport_name;
127 char *protocol_name;
128 u8 subclass;
129 u8 protocol;
130 u8 max_lun;
131
132 u8 ifnum; /* interface number */
133 u8 ep_bInterval; /* interrupt interval */
134
135 /* function pointers for this device */