From fa75ac379e63c2864e9049b5e8615e40f65c1e70 Mon Sep 17 00:00:00 2001 From: Sarah Sharp Date: Sun, 5 Jun 2011 23:10:04 -0700 Subject: xhci: Reject double add of active endpoints. While trying to switch a UAS device from the BOT configuration to the UAS configuration via the bConfigurationValue file, Tanya ran into an issue in the USB core. usb_disable_device() sets entries in udev->ep_out and udev->ep_out to NULL, but doesn't call into the xHCI bandwidth management functions to remove the BOT configuration endpoints from the xHCI host's internal structures. The USB core would then attempt to add endpoints for the UAS configuration, and some of the endpoints had the same address as endpoints in the BOT configuration. The xHCI driver blindly added the endpoints again, but the xHCI host controller rejected the Configure Endpoint command because active endpoints were added without being dropped. Make the xHCI driver reject calls to xhci_add_endpoint() that attempt to add active endpoints without first calling xhci_drop_endpoint(). This should be backported to kernels as old as 2.6.31. Signed-off-by: Sarah Sharp Reported-by: Tanya Brokhman Cc: stable@kernel.org --- drivers/usb/host/xhci.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 06e7023258d..e5a01713f93 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -1401,6 +1401,7 @@ int xhci_add_endpoint(struct usb_hcd *hcd, struct usb_device *udev, u32 added_ctxs; unsigned int last_ctx; u32 new_add_flags, new_drop_flags, new_slot_info; + struct xhci_virt_device *virt_dev; int ret = 0; ret = xhci_check_args(hcd, udev, ep, 1, true, __func__); @@ -1425,11 +1426,25 @@ int xhci_add_endpoint(struct usb_hcd *hcd, struct usb_device *udev, return 0; } - in_ctx = xhci->devs[udev->slot_id]->in_ctx; - out_ctx = xhci->devs[udev->slot_id]->out_ctx; + virt_dev = xhci->devs[udev->slot_id]; + in_ctx = virt_dev->in_ctx; + out_ctx = virt_dev->out_ctx; ctrl_ctx = xhci_get_input_control_ctx(xhci, in_ctx); ep_index = xhci_get_endpoint_index(&ep->desc); ep_ctx = xhci_get_ep_ctx(xhci, out_ctx, ep_index); + + /* If this endpoint is already in use, and the upper layers are trying + * to add it again without dropping it, reject the addition. + */ + if (virt_dev->eps[ep_index].ring && + !(le32_to_cpu(ctrl_ctx->drop_flags) & + xhci_get_endpoint_flag(&ep->desc))) { + xhci_warn(xhci, "Trying to add endpoint 0x%x " + "without dropping it.\n", + (unsigned int) ep->desc.bEndpointAddress); + return -EINVAL; + } + /* If the HCD has already noted the endpoint is enabled, * ignore this request. */ @@ -1445,8 +1460,7 @@ int xhci_add_endpoint(struct usb_hcd *hcd, struct usb_device *udev, * process context, not interrupt context (or so documenation * for usb_set_interface() and usb_set_configuration() claim). */ - if (xhci_endpoint_init(xhci, xhci->devs[udev->slot_id], - udev, ep, GFP_NOIO) < 0) { + if (xhci_endpoint_init(xhci, virt_dev, udev, ep, GFP_NOIO) < 0) { dev_dbg(&udev->dev, "%s - could not initialize ep %#x\n", __func__, ep->desc.bEndpointAddress); return -ENOMEM; -- cgit v1.2.3-18-g5258 From fccf4e86200b8f5edd9a65da26f150e32ba79808 Mon Sep 17 00:00:00 2001 From: Sarah Sharp Date: Sun, 5 Jun 2011 23:22:22 -0700 Subject: USB: Free bandwidth when usb_disable_device is called. Tanya ran into an issue when trying to switch a UAS device from the BOT configuration to the UAS configuration via the bConfigurationValue sysfs file. Before installing the UAS configuration, set_bConfigurationValue() calls usb_disable_device(). That function is supposed to remove all host controller resources associated with that device, but it leaves some state in the xHCI host controller. Commit 0791971ba8fbc44e4f476079f856335ed45e6324 usb: allow drivers to use allocated bandwidth until unbound added a call to usb_disable_device() in usb_set_configuration(), before the xHCI bandwidth functions were invoked. That commit fixed a bug, but also introduced a bug that is triggered when a configured device is switched to a new configuration. usb_disable_device() goes through all the motions of unbinding the drivers attached to active interfaces and removing the USB core structures associated with those interfaces, but it doesn't actually remove the endpoints from the internal xHCI host controller bandwidth structures. When usb_disable_device() calls usb_disable_endpoint() with reset_hardware set to true, the entries in udev->ep_out and udev->ep_in will be set to NULL. Usually, when the USB core installs a new configuration, usb_hcd_alloc_bandwidth() will drop all non-NULL endpoints in udev->ep_out and udev->ep_in before adding any new endpoints. However, when the new UAS configuration was added, all those entries were null, so none of the old endpoints in the BOT configuration were dropped. The xHCI driver blindly added the UAS configuration endpoints, and some of the endpoint addresses overlapped with the old BOT configuration endpoints. This caused the xHCI host to reject the Configure Endpoint command. Now that the xHCI driver code is cleaned up to reject a double-add of active endpoints, we need to fix the USB core to properly drop old endpoints in usb_disable_device(). If the host controller driver needs bandwidth checking support, make usb_disable_device() call usb_disable_endpoint() with reset_hardware set to false, drop the endpoints from the xHCI host controller, and then call usb_disable_endpoint() again with reset_hardware set to true. The first call to usb_disable_endpoint() will cancel any pending URBs and wait on them to be freed in usb_hcd_disable_endpoint(), but will keep the pointers in udev->ep_out and udev->ep in intact. Then usb_hcd_alloc_bandwidth() will use those pointers to know which endpoints to drop. The final call to usb_disable_endpoint() will do two things: 1. It will call usb_hcd_disable_endpoint() again, which should be harmless since the ep->urb_list should be empty after the first call to usb_disable_endpoint() returns. 2. It will set the entries in udev->ep_out and udev->ep in to NULL, and call usb_hcd_disable_endpoint(). That call will have no effect, since the xHCI driver doesn't set the endpoint_disable function pointer. Note that usb_disable_device() will now need to be called with hcd->bandwidth_mutex held. This should be backported to kernels as old as 2.6.32. Signed-off-by: Sarah Sharp Reported-by: Tanya Brokhman Cc: ablay@codeaurora.org Cc: Alan Stern Cc: stable@kernel.org --- drivers/usb/core/hub.c | 3 +++ drivers/usb/core/message.c | 15 ++++++++++++++- 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 90ae1753dda..ca339bc799e 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1634,6 +1634,7 @@ void usb_disconnect(struct usb_device **pdev) { struct usb_device *udev = *pdev; int i; + struct usb_hcd *hcd = bus_to_hcd(udev->bus); if (!udev) { pr_debug ("%s nodev\n", __func__); @@ -1661,7 +1662,9 @@ void usb_disconnect(struct usb_device **pdev) * so that the hardware is now fully quiesced. */ dev_dbg (&udev->dev, "unregistering device\n"); + mutex_lock(hcd->bandwidth_mutex); usb_disable_device(udev, 0); + mutex_unlock(hcd->bandwidth_mutex); usb_hcd_synchronize_unlinks(udev); usb_remove_ep_devs(&udev->ep0); diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index 5701e857392..64c7ab4702d 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1135,10 +1135,13 @@ void usb_disable_interface(struct usb_device *dev, struct usb_interface *intf, * Deallocates hcd/hardware state for the endpoints (nuking all or most * pending urbs) and usbcore state for the interfaces, so that usbcore * must usb_set_configuration() before any interfaces could be used. + * + * Must be called with hcd->bandwidth_mutex held. */ void usb_disable_device(struct usb_device *dev, int skip_ep0) { int i; + struct usb_hcd *hcd = bus_to_hcd(dev->bus); /* getting rid of interfaces will disconnect * any drivers bound to them (a key side effect) @@ -1172,6 +1175,16 @@ void usb_disable_device(struct usb_device *dev, int skip_ep0) dev_dbg(&dev->dev, "%s nuking %s URBs\n", __func__, skip_ep0 ? "non-ep0" : "all"); + if (hcd->driver->check_bandwidth) { + /* First pass: Cancel URBs, leave endpoint pointers intact. */ + for (i = skip_ep0; i < 16; ++i) { + usb_disable_endpoint(dev, i, false); + usb_disable_endpoint(dev, i + USB_DIR_IN, false); + } + /* Remove endpoints from the host controller internal state */ + usb_hcd_alloc_bandwidth(dev, NULL, NULL, NULL); + /* Second pass: remove endpoint pointers */ + } for (i = skip_ep0; i < 16; ++i) { usb_disable_endpoint(dev, i, true); usb_disable_endpoint(dev, i + USB_DIR_IN, true); @@ -1727,6 +1740,7 @@ free_interfaces: /* if it's already configured, clear out old state first. * getting rid of old interfaces means unbinding their drivers. */ + mutex_lock(hcd->bandwidth_mutex); if (dev->state != USB_STATE_ADDRESS) usb_disable_device(dev, 1); /* Skip ep0 */ @@ -1739,7 +1753,6 @@ free_interfaces: * host controller will not allow submissions to dropped endpoints. If * this call fails, the device state is unchanged. */ - mutex_lock(hcd->bandwidth_mutex); ret = usb_hcd_alloc_bandwidth(dev, cp, NULL, NULL); if (ret < 0) { mutex_unlock(hcd->bandwidth_mutex); -- cgit v1.2.3-18-g5258 From d23336329fa4c157ed6256d4279a73b87486a1b6 Mon Sep 17 00:00:00 2001 From: Sarah Sharp Date: Mon, 6 Jun 2011 00:53:47 -0700 Subject: xhci: Don't warn about zeroed bMaxBurst descriptor field. The USB 3.0 specification says that the bMaxBurst field in the SuperSpeed Endpoint Companion descriptor is supposed to indicate how many packets a SS device can handle before it needs to wait for an explicit handshake from the host controller. A zero value means the device can only handle one packet before it needs a handshake. Remove a warning in the xHCI driver that implies this is an invalid value. Signed-off-by: Sarah Sharp --- drivers/usb/host/xhci-mem.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index 0f8e1d29a85..fcb7f7efc86 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -1215,8 +1215,6 @@ int xhci_endpoint_init(struct xhci_hcd *xhci, ep_ctx->ep_info2 |= cpu_to_le32(MAX_PACKET(max_packet)); /* dig out max burst from ep companion desc */ max_packet = ep->ss_ep_comp.bMaxBurst; - if (!max_packet) - xhci_warn(xhci, "WARN no SS endpoint bMaxBurst\n"); ep_ctx->ep_info2 |= cpu_to_le32(MAX_BURST(max_packet)); break; case USB_SPEED_HIGH: -- cgit v1.2.3-18-g5258 From e1cf486d881d853d710e2d86a7adfc5fd260990f Mon Sep 17 00:00:00 2001 From: Alex He Date: Fri, 3 Jun 2011 15:58:25 +0800 Subject: xHCI 1.0: Force Stopped Event(FSE) FSE shall occur on the TD natural boundary. The software ep_ring dequeue pointer exceed the hardware ep_ring dequeue pointer in these cases of Table-3. As a result, the event_trb(pointed by hardware dequeue pointer) of the FSE can't be found in the current TD(pointed by software dequeue pointer). What should we do is to figured out the FSE case and skip over it. Signed-off-by: Alex He Signed-off-by: Sarah Sharp --- drivers/usb/host/xhci-ring.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 800f417c730..0c008497edf 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2063,6 +2063,20 @@ static int handle_tx_event(struct xhci_hcd *xhci, /* Is this a TRB in the currently executing TD? */ event_seg = trb_in_td(ep_ring->deq_seg, ep_ring->dequeue, td->last_trb, event_dma); + + /* + * Skip the Force Stopped Event. The event_trb(event_dma) of FSE + * is not in the current TD pointed by ep_ring->dequeue because + * that the hardware dequeue pointer still at the previous TRB + * of the current TD. The previous TRB maybe a Link TD or the + * last TRB of the previous TD. The command completion handle + * will take care the rest. + */ + if (!event_seg && trb_comp_code == COMP_STOP_INVAL) { + ret = 0; + goto cleanup; + } + if (!event_seg) { if (!ep->skip || !usb_endpoint_xfer_isoc(&td->urb->ep->desc)) { -- cgit v1.2.3-18-g5258 From f6ba6fe2d913da6707a71a413d6ec8ae98d6ce18 Mon Sep 17 00:00:00 2001 From: Alex He Date: Wed, 8 Jun 2011 18:34:06 +0800 Subject: xHCI 1.0: Incompatible Device Error It is one new TRB Completion Code for the xHCI spec v1.0. Asserted if the xHC detects a problem with a device that does not allow it to be successfully accessed, e.g. due to a device compliance or compatibility problem. This error may be returned by any command or transfer, and is fatal as far as the Slot is concerned. Return -EPROTO by urb->status or frame->status of ISOC for transfer case. And return -ENODEV for configure endpoint command, evaluate context command and address device command if there is an incompatible Device Error. The error codes will be sent back to the USB core to decide how to do. It's unnecessary for other commands because after the three commands run successfully means that the device has been accepted. Signed-off-by: Alex He Signed-off-by: Sarah Sharp --- drivers/usb/host/xhci-ring.c | 5 +++++ drivers/usb/host/xhci.c | 15 +++++++++++++++ drivers/usb/host/xhci.h | 2 ++ 3 files changed, 22 insertions(+) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 0c008497edf..436332aa341 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1733,6 +1733,7 @@ static int process_isoc_td(struct xhci_hcd *xhci, struct xhci_td *td, frame->status = -EOVERFLOW; skip_td = true; break; + case COMP_DEV_ERR: case COMP_STALL: frame->status = -EPROTO; skip_td = true; @@ -2016,6 +2017,10 @@ static int handle_tx_event(struct xhci_hcd *xhci, TRB_TO_SLOT_ID(le32_to_cpu(event->flags)), ep_index); goto cleanup; + case COMP_DEV_ERR: + xhci_warn(xhci, "WARN: detect an incompatible device"); + status = -EPROTO; + break; case COMP_MISSED_INT: /* * When encounter missed service error, one or more isoc tds diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index e5a01713f93..15eb4c3d793 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -1551,6 +1551,11 @@ static int xhci_configure_endpoint_result(struct xhci_hcd *xhci, "and endpoint is not disabled.\n"); ret = -EINVAL; break; + case COMP_DEV_ERR: + dev_warn(&udev->dev, "ERROR: Incompatible device for endpoint " + "configure command.\n"); + ret = -ENODEV; + break; case COMP_SUCCESS: dev_dbg(&udev->dev, "Successful Endpoint Configure command\n"); ret = 0; @@ -1585,6 +1590,11 @@ static int xhci_evaluate_context_result(struct xhci_hcd *xhci, xhci_dbg_ctx(xhci, virt_dev->out_ctx, 1); ret = -EINVAL; break; + case COMP_DEV_ERR: + dev_warn(&udev->dev, "ERROR: Incompatible device for evaluate " + "context command.\n"); + ret = -ENODEV; + break; case COMP_MEL_ERR: /* Max Exit Latency too large error */ dev_warn(&udev->dev, "WARN: Max Exit Latency too large\n"); @@ -2867,6 +2877,11 @@ int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev) dev_warn(&udev->dev, "Device not responding to set address.\n"); ret = -EPROTO; break; + case COMP_DEV_ERR: + dev_warn(&udev->dev, "ERROR: Incompatible device for address " + "device command.\n"); + ret = -ENODEV; + break; case COMP_SUCCESS: xhci_dbg(xhci, "Successful Address Device command\n"); break; diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 7d1ea3bf5e1..ba90af1c34b 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -874,6 +874,8 @@ struct xhci_transfer_event { #define COMP_PING_ERR 20 /* Event Ring is full */ #define COMP_ER_FULL 21 +/* Incompatible Device Error */ +#define COMP_DEV_ERR 22 /* Missed Service Error - HC couldn't service an isoc ep within interval */ #define COMP_MISSED_INT 23 /* Successfully stopped command ring */ -- cgit v1.2.3-18-g5258 From c877b3b2ad5cb9d4fe523c5496185cc328ff3ae9 Mon Sep 17 00:00:00 2001 From: Maarten Lankhorst Date: Wed, 15 Jun 2011 23:47:21 +0200 Subject: xhci: Add reset on resume quirk for asrock p67 host The asrock p67 xhci controller completely dies on resume, add a quirk for this, to bring the host back online after a suspend. This should be backported to stable kernels as old as 2.6.37. Signed-off-by: Maarten Lankhorst Signed-off-by: Sarah Sharp Cc: stable@kernel.org --- drivers/usb/host/xhci-pci.c | 8 ++++++++ drivers/usb/host/xhci.c | 2 ++ drivers/usb/host/xhci.h | 1 + 3 files changed, 11 insertions(+) diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c index 17541d09eab..cb16de213f6 100644 --- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -29,6 +29,9 @@ #define PCI_VENDOR_ID_FRESCO_LOGIC 0x1b73 #define PCI_DEVICE_ID_FRESCO_LOGIC_PDK 0x1000 +#define PCI_VENDOR_ID_ETRON 0x1b6f +#define PCI_DEVICE_ID_ASROCK_P67 0x7023 + static const char hcd_name[] = "xhci_hcd"; /* called after powerup, by probe or system-pm "wakeup" */ @@ -134,6 +137,11 @@ static int xhci_pci_setup(struct usb_hcd *hcd) xhci->quirks |= XHCI_EP_LIMIT_QUIRK; xhci->limit_active_eps = 64; } + if (pdev->vendor == PCI_VENDOR_ID_ETRON && + pdev->device == PCI_DEVICE_ID_ASROCK_P67) { + xhci->quirks |= XHCI_RESET_ON_RESUME; + xhci_dbg(xhci, "QUIRK: Resetting on resume\n"); + } /* Make sure the HC is halted. */ retval = xhci_halt(xhci); diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 15eb4c3d793..f5fe1ac301a 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -759,6 +759,8 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated) msleep(100); spin_lock_irq(&xhci->lock); + if (xhci->quirks & XHCI_RESET_ON_RESUME) + hibernated = true; if (!hibernated) { /* step 1: restore register */ diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index ba90af1c34b..d8bbf5ccb10 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1310,6 +1310,7 @@ struct xhci_hcd { */ #define XHCI_EP_LIMIT_QUIRK (1 << 5) #define XHCI_BROKEN_MSI (1 << 6) +#define XHCI_RESET_ON_RESUME (1 << 7) unsigned int num_active_eps; unsigned int limit_active_eps; /* There are two roothubs to keep track of bus suspend info for */ -- cgit v1.2.3-18-g5258 From b3df3f9c7df9a8d85e03e158d35487618a160901 Mon Sep 17 00:00:00 2001 From: Sarah Sharp Date: Wed, 15 Jun 2011 19:57:46 -0700 Subject: xhci: Always set urb->status to zero for isoc endpoints. When the xHCI driver encounters a Missed Service Interval event for an isochronous endpoint ring, it means the host controller skipped over one or more isochronous TDs. For TD that is skipped, skip_isoc_td() is called. This sets the frame descriptor status to -EXDEV, and also sets the value stored in the int pointed to by status to -EXDEV. If the isochronous TD happens to be the last TD in an URB, handle_tx_event() will use the status variable to give back the URB to the USB core. That means drivers will see urb->status as -EXDEV. It turns out that EHCI, UHCI, and OHCI always set urb->status to zero for an isochronous urb, regardless of what the frame status is. See itd_complete() in ehci-sched.c: } else { /* URB was too late */ desc->status = -EXDEV; } } /* handle completion now? */ if (likely ((urb_index + 1) != urb->number_of_packets)) goto done; /* ASSERT: it's really the last itd for this urb list_for_each_entry (itd, &stream->td_list, itd_list) BUG_ON (itd->urb == urb); */ /* give urb back to the driver; completion often (re)submits */ dev = urb->dev; ehci_urb_done(ehci, urb, 0); ehci_urb_done() completes the URB with the status of the third argument, which is always zero in this case. It turns out that many USB webcam drivers, such as uvcvideo, cannot handle urb->status set to a non-zero value. They will not resubmit their isochronous URBs in that case, and userspace will see a frozen video. Change the xHCI driver to be consistent with the EHCI and UHCI driver, and always set urb->status to 0 for isochronous URBs. This patch should be backported to kernels as old as 2.6.36 Signed-off-by: Sarah Sharp Cc: "Xu, Andiry" Cc: stable@kernel.org --- drivers/usb/host/xhci-ring.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 436332aa341..70cacbbe7fb 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1768,9 +1768,6 @@ static int process_isoc_td(struct xhci_hcd *xhci, struct xhci_td *td, } } - if ((idx == urb_priv->length - 1) && *status == -EINPROGRESS) - *status = 0; - return finish_td(xhci, td, event_trb, event, ep, status, false); } @@ -1788,8 +1785,7 @@ static int skip_isoc_td(struct xhci_hcd *xhci, struct xhci_td *td, idx = urb_priv->td_cnt; frame = &td->urb->iso_frame_desc[idx]; - /* The transfer is partly done */ - *status = -EXDEV; + /* The transfer is partly done. */ frame->status = -EXDEV; /* calc actual length */ @@ -2177,6 +2173,11 @@ cleanup: urb->transfer_buffer_length, status); spin_unlock(&xhci->lock); + /* EHCI, UHCI, and OHCI always unconditionally set the + * urb->status of an isochronous endpoint to 0. + */ + if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) + status = 0; usb_hcd_giveback_urb(bus_to_hcd(urb->dev->bus), urb, status); spin_lock(&xhci->lock); } -- cgit v1.2.3-18-g5258 From a9e758634f464ffb09344821a9f0b5a5c6df2b3e Mon Sep 17 00:00:00 2001 From: Sarah Sharp Date: Thu, 16 Jun 2011 13:06:04 -0700 Subject: USB: Fix up URB error codes to reflect implementation. Documentation/usb/error-codes.txt mentions that urb->status can be set to -EXDEV, if the isochronous transfer was not fully completed. However, in practice, EHCI, UHCI, and OHCI all only set -EXDEV in the individual frame status, never in the URB status. Those host controller actually always pass in a zero status to usb_hcd_giveback_urb, and rely on the core to set the appropriate status value. The xHCI driver ran into issues with the uvcvideo driver when it tried to set -EXDEV in urb->status, because the driver refused to submit URBs, and the userspace camera application's video froze. Clean up the documentation to reflect the actual implementation. Signed-off-by: Sarah Sharp Acked-by: Alan Stern --- Documentation/usb/error-codes.txt | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/Documentation/usb/error-codes.txt b/Documentation/usb/error-codes.txt index d83703ea74b..b3f606b81a0 100644 --- a/Documentation/usb/error-codes.txt +++ b/Documentation/usb/error-codes.txt @@ -76,6 +76,13 @@ A transfer's actual_length may be positive even when an error has been reported. That's because transfers often involve several packets, so that one or more packets could finish before an error stops further endpoint I/O. +For isochronous URBs, the urb status value is non-zero only if the URB is +unlinked, the device is removed, the host controller is disabled, or the total +transferred length is less than the requested length and the URB_SHORT_NOT_OK +flag is set. Completion handlers for isochronous URBs should only see +urb->status set to zero, -ENOENT, -ECONNRESET, -ESHUTDOWN, or -EREMOTEIO. +Individual frame descriptor status fields may report more status codes. + 0 Transfer completed successfully @@ -132,7 +139,7 @@ one or more packets could finish before an error stops further endpoint I/O. device removal events immediately. -EXDEV ISO transfer only partially completed - look at individual frame status for details + (only set in iso_frame_desc[n].status, not urb->status) -EINVAL ISO madness, if this happens: Log off and go home -- cgit v1.2.3-18-g5258