From a23aeaba3c43eb0aae463a95af245284bf7942cf Mon Sep 17 00:00:00 2001 From: P33M Date: Thu, 21 Mar 2013 19:36:17 +0000 Subject: [PATCH] dwc_otg: implement tasklet for returning URBs to usbcore hcd layer The dwc_otg driver interrupt handler for transfer completion will spend a very long time with interrupts disabled when a URB is completed - this is because usb_hcd_giveback_urb is called from within the handler which for a USB device driver with complicated processing (e.g. webcam) will take an exorbitant amount of time to complete. This results in missed completion interrupts for other USB packets which lead to them being dropped due to microframe overruns. This patch splits returning the URB to the usb hcd layer into a high-priority tasklet. This will have most benefit for isochronous IN transfers but will also have incidental benefit where multiple periodic devices are active at once. --- .../host/dwc_common_port/dwc_common_linux.c | 5 +++ drivers/usb/host/dwc_common_port/dwc_list.h | 14 ++++---- drivers/usb/host/dwc_common_port/dwc_os.h | 2 ++ drivers/usb/host/dwc_otg/dwc_otg_hcd.c | 34 ++++++++++++++++++- drivers/usb/host/dwc_otg/dwc_otg_hcd.h | 10 ++++++ drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c | 25 +++++++++----- 6 files changed, 73 insertions(+), 17 deletions(-) diff --git a/drivers/usb/host/dwc_common_port/dwc_common_linux.c b/drivers/usb/host/dwc_common_port/dwc_common_linux.c index 440bcfc030fdc2..1788812c6f95da 100644 --- a/drivers/usb/host/dwc_common_port/dwc_common_linux.c +++ b/drivers/usb/host/dwc_common_port/dwc_common_linux.c @@ -991,6 +991,11 @@ void DWC_TASK_SCHEDULE(dwc_tasklet_t *task) tasklet_schedule(&task->t); } +void DWC_TASK_HI_SCHEDULE(dwc_tasklet_t *task) +{ + tasklet_hi_schedule(&task->t); +} + /* workqueues - run in process context (can sleep) diff --git a/drivers/usb/host/dwc_common_port/dwc_list.h b/drivers/usb/host/dwc_common_port/dwc_list.h index 89cc325045fc36..4ce560df0cae63 100644 --- a/drivers/usb/host/dwc_common_port/dwc_list.h +++ b/drivers/usb/host/dwc_common_port/dwc_list.h @@ -384,17 +384,17 @@ struct { \ #define DWC_TAILQ_PREV(elm, headname, field) \ (*(((struct headname *)((elm)->field.tqe_prev))->tqh_last)) #define DWC_TAILQ_EMPTY(head) \ - (TAILQ_FIRST(head) == TAILQ_END(head)) + (DWC_TAILQ_FIRST(head) == DWC_TAILQ_END(head)) #define DWC_TAILQ_FOREACH(var, head, field) \ - for((var) = TAILQ_FIRST(head); \ - (var) != TAILQ_END(head); \ - (var) = TAILQ_NEXT(var, field)) + for ((var) = DWC_TAILQ_FIRST(head); \ + (var) != DWC_TAILQ_END(head); \ + (var) = DWC_TAILQ_NEXT(var, field)) #define DWC_TAILQ_FOREACH_REVERSE(var, head, headname, field) \ - for((var) = TAILQ_LAST(head, headname); \ - (var) != TAILQ_END(head); \ - (var) = TAILQ_PREV(var, headname, field)) + for ((var) = DWC_TAILQ_LAST(head, headname); \ + (var) != DWC_TAILQ_END(head); \ + (var) = DWC_TAILQ_PREV(var, headname, field)) /* * Tail queue functions. diff --git a/drivers/usb/host/dwc_common_port/dwc_os.h b/drivers/usb/host/dwc_common_port/dwc_os.h index 9ffe9293d5f93f..09ed244b1414a2 100644 --- a/drivers/usb/host/dwc_common_port/dwc_os.h +++ b/drivers/usb/host/dwc_common_port/dwc_os.h @@ -981,6 +981,8 @@ extern void DWC_TASK_FREE(dwc_tasklet_t *task); extern void DWC_TASK_SCHEDULE(dwc_tasklet_t *task); #define dwc_task_schedule DWC_TASK_SCHEDULE +extern void DWC_TASK_HI_SCHEDULE(dwc_tasklet_t *task); +#define dwc_task_hi_schedule DWC_TASK_HI_SCHEDULE /** @name Timer * diff --git a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c index 6fe30e3574f793..533b17d58e45aa 100644 --- a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c +++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c @@ -40,6 +40,9 @@ * header file. */ +#include +#include + #include "dwc_otg_hcd.h" #include "dwc_otg_regs.h" @@ -694,6 +697,31 @@ static void reset_tasklet_func(void *data) dwc_otg_hcd->flags.b.port_reset_change = 1; } +static void completion_tasklet_func(void *ptr) +{ + dwc_otg_hcd_t *hcd = (dwc_otg_hcd_t *) ptr; + struct urb *urb; + urb_tq_entry_t *item; + dwc_irqflags_t flags; + + DWC_SPINLOCK_IRQSAVE(hcd->lock, &flags); + while (!DWC_TAILQ_EMPTY(&hcd->completed_urb_list)) { + item = DWC_TAILQ_FIRST(&hcd->completed_urb_list); + urb = item->urb; + DWC_TAILQ_REMOVE(&hcd->completed_urb_list, item, + urb_tq_entries); + DWC_SPINUNLOCK_IRQRESTORE(hcd->lock, flags); + DWC_FREE(item); + + usb_hcd_unlink_urb_from_ep(hcd->priv, urb); + usb_hcd_giveback_urb(hcd->priv, urb, urb->status); + + DWC_SPINLOCK_IRQSAVE(hcd->lock, &flags); + } + DWC_SPINUNLOCK_IRQRESTORE(hcd->lock, flags); + return; +} + static void qh_list_free(dwc_otg_hcd_t * hcd, dwc_list_link_t * qh_list) { dwc_list_link_t *item; @@ -833,6 +861,7 @@ static void dwc_otg_hcd_free(dwc_otg_hcd_t * dwc_otg_hcd) DWC_TIMER_FREE(dwc_otg_hcd->conn_timer); DWC_TASK_FREE(dwc_otg_hcd->reset_tasklet); + DWC_TASK_FREE(dwc_otg_hcd->completion_tasklet); #ifdef DWC_DEV_SRPCAP if (dwc_otg_hcd->core_if->power_down == 2 && @@ -877,7 +906,7 @@ int dwc_otg_hcd_init(dwc_otg_hcd_t * hcd, dwc_otg_core_if_t * core_if) DWC_LIST_INIT(&hcd->periodic_sched_ready); DWC_LIST_INIT(&hcd->periodic_sched_assigned); DWC_LIST_INIT(&hcd->periodic_sched_queued); - + DWC_TAILQ_INIT(&hcd->completed_urb_list); /* * Create a host channel descriptor for each host channel implemented * in the controller. Initialize the channel descriptor array. @@ -915,6 +944,9 @@ int dwc_otg_hcd_init(dwc_otg_hcd_t * hcd, dwc_otg_core_if_t * core_if) /* Initialize reset tasklet. */ hcd->reset_tasklet = DWC_TASK_ALLOC("reset_tasklet", reset_tasklet_func, hcd); + + hcd->completion_tasklet = DWC_TASK_ALLOC("completion_tasklet", + completion_tasklet_func, hcd); #ifdef DWC_DEV_SRPCAP if (hcd->core_if->power_down == 2) { /* Initialize Power on timer for Host power up in case hibernation */ diff --git a/drivers/usb/host/dwc_otg/dwc_otg_hcd.h b/drivers/usb/host/dwc_otg/dwc_otg_hcd.h index 0827b199d650aa..0ba7558de1911f 100644 --- a/drivers/usb/host/dwc_otg/dwc_otg_hcd.h +++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd.h @@ -374,6 +374,13 @@ typedef struct dwc_otg_qh { DWC_CIRCLEQ_HEAD(hc_list, dwc_hc); +typedef struct urb_tq_entry { + struct urb *urb; + DWC_TAILQ_ENTRY(urb_tq_entry) urb_tq_entries; +} urb_tq_entry_t; + +DWC_TAILQ_HEAD(urb_list, urb_tq_entry); + /** * This structure holds the state of the HCD, including the non-periodic and * periodic schedules. @@ -551,6 +558,9 @@ struct dwc_otg_hcd { /* Tasket to do a reset */ dwc_tasklet_t *reset_tasklet; + dwc_tasklet_t *completion_tasklet; + struct urb_list completed_urb_list; + /* */ dwc_spinlock_t *lock; dwc_spinlock_t *channel_lock; diff --git a/drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c b/drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c index 2b4a14e1ed7278..39787e3ffa5927 100644 --- a/drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c +++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c @@ -271,7 +271,7 @@ static int _complete(dwc_otg_hcd_t * hcd, void *urb_handle, dwc_otg_hcd_urb_t * dwc_otg_urb, int32_t status) { struct urb *urb = (struct urb *)urb_handle; - + urb_tq_entry_t *new_entry; if (CHK_DEBUG_LEVEL(DBG_HCDV | DBG_HCD_URB)) { DWC_PRINTF("%s: urb %p, device %d, ep %d %s, status=%d\n", __func__, urb, usb_pipedevice(urb->pipe), @@ -285,7 +285,7 @@ static int _complete(dwc_otg_hcd_t * hcd, void *urb_handle, } } } - + new_entry = DWC_ALLOC_ATOMIC(sizeof(urb_tq_entry_t)); urb->actual_length = dwc_otg_hcd_urb_get_actual_length(dwc_otg_urb); /* Convert status value. */ switch (status) { @@ -348,18 +348,25 @@ static int _complete(dwc_otg_hcd_t * hcd, void *urb_handle, } DWC_FREE(dwc_otg_urb); - + if (!new_entry) { + DWC_ERROR("dwc_otg_hcd: complete: cannot allocate URB TQ entry\n"); + urb->status = -EPROTO; + /* don't schedule the tasklet - + * directly return the packet here with error. */ #if USB_URB_EP_LINKING - usb_hcd_unlink_urb_from_ep(dwc_otg_hcd_to_hcd(hcd), urb); + usb_hcd_unlink_urb_from_ep(dwc_otg_hcd_to_hcd(hcd), urb); #endif - DWC_SPINUNLOCK(hcd->lock); #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,28) - usb_hcd_giveback_urb(dwc_otg_hcd_to_hcd(hcd), urb); + usb_hcd_giveback_urb(dwc_otg_hcd_to_hcd(hcd), urb); #else - usb_hcd_giveback_urb(dwc_otg_hcd_to_hcd(hcd), urb, status); + usb_hcd_giveback_urb(dwc_otg_hcd_to_hcd(hcd), urb, urb->status); #endif - DWC_SPINLOCK(hcd->lock); - + } else { + new_entry->urb = urb; + DWC_TAILQ_INSERT_TAIL(&hcd->completed_urb_list, new_entry, + urb_tq_entries); + DWC_TASK_HI_SCHEDULE(hcd->completion_tasklet); + } return 0; }