diff options
Diffstat (limited to 'drivers/usb/host/uhci-hcd.h')
| -rw-r--r-- | drivers/usb/host/uhci-hcd.h | 74 |
1 files changed, 36 insertions, 38 deletions
diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h index a8c256b44d8..1b3d23406ac 100644 --- a/drivers/usb/host/uhci-hcd.h +++ b/drivers/usb/host/uhci-hcd.h @@ -135,7 +135,6 @@ struct uhci_qh { struct usb_host_endpoint *hep; /* Endpoint information */ struct usb_device *udev; struct list_head queue; /* Queue of urbps for this QH */ - struct uhci_qh *skel; /* Skeleton for this QH */ struct uhci_td *dummy_td; /* Dummy TD to end the queue */ struct uhci_td *post_td; /* Last TD completed */ @@ -151,6 +150,7 @@ struct uhci_qh { int state; /* QH_STATE_xxx; see above */ int type; /* Queue type (control, bulk, etc) */ + int skel; /* Skeleton queue number */ unsigned int initial_toggle:1; /* Endpoint's current toggle value */ unsigned int needs_fixup:1; /* Must fix the TD toggle values */ @@ -276,12 +276,13 @@ static inline u32 td_status(struct uhci_td *td) { /* * The UHCI driver uses QHs with Interrupt, Control and Bulk URBs for * automatic queuing. To make it easy to insert entries into the schedule, - * we have a skeleton of QHs for each predefined Interrupt latency, - * low-speed control, full-speed control, bulk, and terminating QH - * (see explanation for the terminating QH below). + * we have a skeleton of QHs for each predefined Interrupt latency. + * Asynchronous QHs (low-speed control, full-speed control, and bulk) + * go onto the period-1 interrupt list, since they all get accessed on + * every frame. * - * When we want to add a new QH, we add it to the end of the list for the - * skeleton QH. For instance, the schedule list can look like this: + * When we want to add a new QH, we add it to the list starting from the + * appropriate skeleton QH. For instance, the schedule can look like this: * * skel int128 QH * dev 1 interrupt QH @@ -289,50 +290,47 @@ static inline u32 td_status(struct uhci_td *td) { * skel int64 QH * skel int32 QH * ... - * skel int1 QH - * skel low-speed control QH - * dev 5 control QH - * skel full-speed control QH - * skel bulk QH + * skel int1 + async QH + * dev 5 low-speed control QH * dev 1 bulk QH * dev 2 bulk QH - * skel terminating QH * - * The terminating QH is used for 2 reasons: - * - To place a terminating TD which is used to workaround a PIIX bug - * (see Intel errata for explanation), and - * - To loop back to the full-speed control queue for full-speed bandwidth - * reclamation. + * There is a special terminating QH used to keep full-speed bandwidth + * reclamation active when no full-speed control or bulk QHs are linked + * into the schedule. It has an inactive TD (to work around a PIIX bug, + * see the Intel errata) and it points back to itself. * - * There's a special skeleton QH for Isochronous QHs. It never appears - * on the schedule, and Isochronous TDs go on the schedule before the + * There's a special skeleton QH for Isochronous QHs which never appears + * on the schedule. Isochronous TDs go on the schedule before the * the skeleton QHs. The hardware accesses them directly rather than * through their QH, which is used only for bookkeeping purposes. * While the UHCI spec doesn't forbid the use of QHs for Isochronous, * it doesn't use them either. And the spec says that queues never * advance on an error completion status, which makes them totally * unsuitable for Isochronous transfers. + * + * There's also a special skeleton QH used for QHs which are in the process + * of unlinking and so may still be in use by the hardware. It too never + * appears on the schedule. */ -#define UHCI_NUM_SKELQH 14 -#define skel_unlink_qh skelqh[0] -#define skel_iso_qh skelqh[1] -#define skel_int128_qh skelqh[2] -#define skel_int64_qh skelqh[3] -#define skel_int32_qh skelqh[4] -#define skel_int16_qh skelqh[5] -#define skel_int8_qh skelqh[6] -#define skel_int4_qh skelqh[7] -#define skel_int2_qh skelqh[8] -#define skel_int1_qh skelqh[9] -#define skel_ls_control_qh skelqh[10] -#define skel_fs_control_qh skelqh[11] -#define skel_bulk_qh skelqh[12] -#define skel_term_qh skelqh[13] - -/* Find the skelqh entry corresponding to an interval exponent */ -#define UHCI_SKEL_INDEX(exponent) (9 - exponent) - +#define UHCI_NUM_SKELQH 11 +#define SKEL_UNLINK 0 +#define skel_unlink_qh skelqh[SKEL_UNLINK] +#define SKEL_ISO 1 +#define skel_iso_qh skelqh[SKEL_ISO] + /* int128, int64, ..., int1 = 2, 3, ..., 9 */ +#define SKEL_INDEX(exponent) (9 - exponent) +#define SKEL_ASYNC 9 +#define skel_async_qh skelqh[SKEL_ASYNC] +#define SKEL_TERM 10 +#define skel_term_qh skelqh[SKEL_TERM] + +/* The following entries refer to sublists of skel_async_qh */ +#define SKEL_LS_CONTROL 20 +#define SKEL_FS_CONTROL 21 +#define SKEL_FSBR SKEL_FS_CONTROL +#define SKEL_BULK 22 /* * The UHCI controller and root hub |