1 /**************************************************************************/
2 /* */
3 /* Copyright (c) Microsoft Corporation. All rights reserved. */
4 /* */
5 /* This software is licensed under the Microsoft Software License */
6 /* Terms for Microsoft Azure RTOS. Full text of the license can be */
7 /* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
8 /* and in the root directory of this software. */
9 /* */
10 /**************************************************************************/
11
12
13 /**************************************************************************/
14 /**************************************************************************/
15 /** */
16 /** USBX Component */
17 /** */
18 /** Host Simulator Controller Driver */
19 /** */
20 /**************************************************************************/
21 /**************************************************************************/
22
23 #define UX_SOURCE_CODE
24
25
26 /* Include necessary system files. */
27
28 #include "ux_api.h"
29 #include "ux_hcd_sim_host.h"
30
31
32 /**************************************************************************/
33 /* */
34 /* FUNCTION RELEASE */
35 /* */
36 /* _ux_hcd_sim_host_ed_td_clean PORTABLE C */
37 /* 6.1 */
38 /* AUTHOR */
39 /* */
40 /* Chaoqiong Xiao, Microsoft Corporation */
41 /* */
42 /* DESCRIPTION */
43 /* */
44 /* This function process cleans the ED of all TDs except the last */
45 /* dummy TD. */
46 /* */
47 /* INPUT */
48 /* */
49 /* ed Pointer to ED */
50 /* */
51 /* OUTPUT */
52 /* */
53 /* None */
54 /* */
55 /* CALLS */
56 /* */
57 /* None */
58 /* */
59 /* CALLED BY */
60 /* */
61 /* Host Simulator Controller Driver */
62 /* */
63 /* RELEASE HISTORY */
64 /* */
65 /* DATE NAME DESCRIPTION */
66 /* */
67 /* 05-19-2020 Chaoqiong Xiao Initial Version 6.0 */
68 /* 09-30-2020 Chaoqiong Xiao Modified comment(s), */
69 /* resulting in version 6.1 */
70 /* */
71 /**************************************************************************/
_ux_hcd_sim_host_ed_td_clean(UX_HCD_SIM_HOST_ED * ed)72 VOID _ux_hcd_sim_host_ed_td_clean(UX_HCD_SIM_HOST_ED *ed)
73 {
74
75 UX_HCD_SIM_HOST_TD *head_td;
76 UX_HCD_SIM_HOST_TD *tail_td;
77
78
79 /* Remove all the tds from this ED and leave the head and tail pointing
80 to the dummy TD. */
81 head_td = ed -> ux_sim_host_ed_head_td;
82 tail_td = ed -> ux_sim_host_ed_tail_td;
83
84 /* Free all tds attached to the ED. */
85 while (head_td != tail_td)
86 {
87
88 /* Mark the current head TD as free. */
89 head_td -> ux_sim_host_td_status = UX_UNUSED;
90
91 /* Update the head TD with the next TD. */
92 ed -> ux_sim_host_ed_head_td = head_td -> ux_sim_host_td_next_td;
93
94 /* Now the new head_td is the next TD in the chain. */
95 head_td = ed -> ux_sim_host_ed_head_td;
96 }
97 }
98
99
