diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-module | 23 | ||||
| -rw-r--r-- | Documentation/usb/ehci.txt | 2 | ||||
| -rw-r--r-- | drivers/usb/host/ehci-hcd.c | 6 | ||||
| -rw-r--r-- | drivers/usb/host/ehci-sched.c | 17 | ||||
| -rw-r--r-- | drivers/usb/host/ehci-sysfs.c | 104 | ||||
| -rw-r--r-- | drivers/usb/host/ehci.h | 2 |
6 files changed, 140 insertions, 14 deletions
diff --git a/Documentation/ABI/testing/sysfs-module b/Documentation/ABI/testing/sysfs-module index cfcec3bffc0a..9489ea8e294c 100644 --- a/Documentation/ABI/testing/sysfs-module +++ b/Documentation/ABI/testing/sysfs-module @@ -10,3 +10,26 @@ KernelVersion: 2.6.35 Contact: masa-korg@dsn.okisemi.com Description: Write/read Option ROM data. + +What: /sys/module/ehci_hcd/drivers/.../uframe_periodic_max +Date: July 2011 +KernelVersion: 3.1 +Contact: Kirill Smelkov <kirr@mns.spb.ru> +Description: Maximum time allowed for periodic transfers per microframe (μs) + + [ USB 2.0 sets maximum allowed time for periodic transfers per + microframe to be 80%, that is 100 microseconds out of 125 + microseconds (full microframe). + + However there are cases, when 80% max isochronous bandwidth is + too limiting. For example two video streams could require 110 + microseconds of isochronous bandwidth per microframe to work + together. ] + + Through this setting it is possible to raise the limit so that + the host controller would allow allocating more than 100 + microseconds of periodic bandwidth per microframe. + + Beware, non-standard modes are usually not thoroughly tested by + hardware designers, and the hardware can malfunction when this + setting differ from default 100. diff --git a/Documentation/usb/ehci.txt b/Documentation/usb/ehci.txt index 9dcafa7d930d..160bd6c3ab7b 100644 --- a/Documentation/usb/ehci.txt +++ b/Documentation/usb/ehci.txt @@ -210,3 +210,5 @@ TBD: Interrupt and ISO transfer performance issues. Those periodic transfers are fully scheduled, so the main issue is likely to be how to trigger "high bandwidth" modes. +TBD: More than standard 80% periodic bandwidth allocation is possible +through sysfs uframe_periodic_max parameter. Describe that. diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 8306155de9e5..4ee62bef3723 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -572,6 +572,12 @@ static int ehci_init(struct usb_hcd *hcd) hcc_params = ehci_readl(ehci, &ehci->caps->hcc_params); /* + * by default set standard 80% (== 100 usec/uframe) max periodic + * bandwidth as required by USB 2.0 + */ + ehci->uframe_periodic_max = 100; + + /* * hw default: 1K periodic list heads, one per frame. * periodic_size can shrink by USBCMD update if hcc_params allows. */ diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index 6c9fbe352f73..2abf8543f083 100644 --- a/drivers/usb/host/ehci-sched.c +++ b/drivers/usb/host/ehci-sched.c @@ -172,7 +172,7 @@ periodic_usecs (struct ehci_hcd *ehci, unsigned frame, unsigned uframe) } } #ifdef DEBUG - if (usecs > 100) + if (usecs > ehci->uframe_periodic_max) ehci_err (ehci, "uframe %d sched overrun: %d usecs\n", frame * 8 + uframe, usecs); #endif @@ -709,11 +709,8 @@ static int check_period ( if (uframe >= 8) return 0; - /* - * 80% periodic == 100 usec/uframe available - * convert "usecs we need" to "max already claimed" - */ - usecs = 100 - usecs; + /* convert "usecs we need" to "max already claimed" */ + usecs = ehci->uframe_periodic_max - usecs; /* we "know" 2 and 4 uframe intervals were rejected; so * for period 0, check _every_ microframe in the schedule. @@ -1286,9 +1283,9 @@ itd_slot_ok ( { uframe %= period; do { - /* can't commit more than 80% periodic == 100 usec */ + /* can't commit more than uframe_periodic_max usec */ if (periodic_usecs (ehci, uframe >> 3, uframe & 0x7) - > (100 - usecs)) + > (ehci->uframe_periodic_max - usecs)) return 0; /* we know urb->interval is 2^N uframes */ @@ -1345,7 +1342,7 @@ sitd_slot_ok ( #endif /* check starts (OUT uses more than one) */ - max_used = 100 - stream->usecs; + max_used = ehci->uframe_periodic_max - stream->usecs; for (tmp = stream->raw_mask & 0xff; tmp; tmp >>= 1, uf++) { if (periodic_usecs (ehci, frame, uf) > max_used) return 0; @@ -1354,7 +1351,7 @@ sitd_slot_ok ( /* for IN, check CSPLIT */ if (stream->c_usecs) { uf = uframe & 7; - max_used = 100 - stream->c_usecs; + max_used = ehci->uframe_periodic_max - stream->c_usecs; do { tmp = 1 << uf; tmp <<= 8; diff --git a/drivers/usb/host/ehci-sysfs.c b/drivers/usb/host/ehci-sysfs.c index 29824a98aec9..14ced00ba220 100644 --- a/drivers/usb/host/ehci-sysfs.c +++ b/drivers/usb/host/ehci-sysfs.c @@ -74,21 +74,117 @@ static ssize_t store_companion(struct device *dev, } static DEVICE_ATTR(companion, 0644, show_companion, store_companion); + +/* + * Display / Set uframe_periodic_max + */ +static ssize_t show_uframe_periodic_max(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct ehci_hcd *ehci; + int n; + + ehci = hcd_to_ehci(bus_to_hcd(dev_get_drvdata(dev))); + n = scnprintf(buf, PAGE_SIZE, "%d\n", ehci->uframe_periodic_max); + return n; +} + + +static ssize_t store_uframe_periodic_max(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct ehci_hcd *ehci; + unsigned uframe_periodic_max; + unsigned frame, uframe; + unsigned short allocated_max; + unsigned long flags; + ssize_t ret; + + ehci = hcd_to_ehci(bus_to_hcd(dev_get_drvdata(dev))); + if (kstrtouint(buf, 0, &uframe_periodic_max) < 0) + return -EINVAL; + + if (uframe_periodic_max < 100 || uframe_periodic_max >= 125) { + ehci_info(ehci, "rejecting invalid request for " + "uframe_periodic_max=%u\n", uframe_periodic_max); + return -EINVAL; + } + + ret = -EINVAL; + + /* + * lock, so that our checking does not race with possible periodic + * bandwidth allocation through submitting new urbs. + */ + spin_lock_irqsave (&ehci->lock, flags); + + /* + * for request to decrease max periodic bandwidth, we have to check + * every microframe in the schedule to see whether the decrease is + * possible. + */ + if (uframe_periodic_max < ehci->uframe_periodic_max) { + allocated_max = 0; + + for (frame = 0; frame < ehci->periodic_size; ++frame) + for (uframe = 0; uframe < 7; ++uframe) + allocated_max = max(allocated_max, + periodic_usecs (ehci, frame, uframe)); + + if (allocated_max > uframe_periodic_max) { + ehci_info(ehci, + "cannot decrease uframe_periodic_max becase " + "periodic bandwidth is already allocated " + "(%u > %u)\n", + allocated_max, uframe_periodic_max); + goto out_unlock; + } + } + + /* increasing is always ok */ + + ehci_info(ehci, "setting max periodic bandwidth to %u%% " + "(== %u usec/uframe)\n", + 100*uframe_periodic_max/125, uframe_periodic_max); + + if (uframe_periodic_max != 100) + ehci_warn(ehci, "max periodic bandwidth set is non-standard\n"); + + ehci->uframe_periodic_max = uframe_periodic_max; + ret = count; + +out_unlock: + spin_unlock_irqrestore (&ehci->lock, flags); + return ret; +} +static DEVICE_ATTR(uframe_periodic_max, 0644, show_uframe_periodic_max, store_uframe_periodic_max); + + static inline int create_sysfs_files(struct ehci_hcd *ehci) { + struct device *controller = ehci_to_hcd(ehci)->self.controller; int i = 0; /* with integrated TT there is no companion! */ if (!ehci_is_TDI(ehci)) - i = device_create_file(ehci_to_hcd(ehci)->self.controller, - &dev_attr_companion); + i = device_create_file(controller, &dev_attr_companion); + if (i) + goto out; + + i = device_create_file(controller, &dev_attr_uframe_periodic_max); +out: return i; } static inline void remove_sysfs_files(struct ehci_hcd *ehci) { + struct device *controller = ehci_to_hcd(ehci)->self.controller; + /* with integrated TT there is no companion! */ if (!ehci_is_TDI(ehci)) - device_remove_file(ehci_to_hcd(ehci)->self.controller, - &dev_attr_companion); + device_remove_file(controller, &dev_attr_companion); + + device_remove_file(controller, &dev_attr_uframe_periodic_max); } diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h index bd6ff489baf9..fa3129fe1ee0 100644 --- a/drivers/usb/host/ehci.h +++ b/drivers/usb/host/ehci.h @@ -87,6 +87,8 @@ struct ehci_hcd { /* one per controller */ union ehci_shadow *pshadow; /* mirror hw periodic table */ int next_uframe; /* scan periodic, start here */ unsigned periodic_sched; /* periodic activity count */ + unsigned uframe_periodic_max; /* max periodic time per uframe */ + /* list of itds & sitds completed while clock_frame was still active */ struct list_head cached_itd_list; 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