linux/include/linux/usb.h

1617 lines
62 KiB

[PATCH] USB: real nodes instead of usbfs This patch introduces a /sys/class/usb_device/ class where every connected usb-device will show up: tree /sys/class/usb_device/ /sys/class/usb_device/ |-- usb1.1 | |-- dev | `-- device -> ../../../devices/pci0000:00/0000:00:1d.0/usb1 |-- usb2.1 | |-- dev | `-- device -> ../../../devices/pci0000:00/0000:00:1d.1/usb2 ... The presence of the "dev" file lets udev create real device nodes. kay@pim:~/src/linux-2.6> tree /dev/bus/usb/ /dev/bus/usb/ |-- 1 | `-- 1 |-- 2 | `-- 1 ... udev rule: SUBSYSTEM="usb_device", PROGRAM="/sbin/usb_device %k", NAME="%c" (echo $1 | /bin/sed 's/usb\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/') This makes libusb pick up the real nodes instead of the mounted usbfs: export USB_DEVFS_PATH=/dev/bus/usb Background: All this makes it possible to manage usb devices with udev instead of the devfs solution. We are currently working on a pam_console/resmgr replacement driven by udev and a pam-helper. It applies ACL's to device nodes, which is required for modern desktop functionalty like "Fast User Switching" or multiple local login support. New patch with its own major. I've succesfully disabled usbfs and use real nodes only on my box. With: "export USB_DEVFS_PATH=/dev/bus/usb" libusb picks up the udev managed nodes instead of reading usbfs files. This makes udev to provide symlinks for libusb to pick up: SUBSYSTEM="usb_device", PROGRAM="/sbin/usbdevice %k", SYMLINK="%c" /sbin/usbdevice: #!/bin/sh echo $1 | /bin/sed 's/usbdev\([0-9]*\)\.\([0-9]*\)/bus\/usb\/\1\/\2/' Signed-off-by: Kay Sievers <kay.sievers@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-07-31 01:05:53 +02:00
USB: Parse and store the SuperSpeed endpoint companion descriptors. The USB 3.0 bus specification added an "Endpoint Companion" descriptor that is supposed to follow all SuperSpeed Endpoint descriptors. This descriptor is used to extend the bus protocol to allow more packets to be sent to an endpoint per "microframe". The word microframe was removed from the USB 3.0 specification because the host controller does not send Start Of Frame (SOF) symbols down the USB 3.0 wires. The descriptor defines a bMaxBurst field, which indicates the number of packets of wMaxPacketSize that a SuperSpeed device can send or recieve in a service interval. All non-control endpoints may set this value as high as 16 packets (bMaxBurst = 15). The descriptor also allows isochronous endpoints to further specify that they can send and receive multiple bursts per service interval. The bmAttributes allows them to specify a "Mult" of up to 3 (bmAttributes = 2). Bulk endpoints use bmAttributes to report the number of "Streams" they support. This was an extension of the endpoint pipe concept to allow multiple mass storage device commands to be outstanding for one bulk endpoint at a time. This should allow USB 3.0 mass storage devices to support SCSI command queueing. Bulk endpoints can say they support up to 2^16 (65,536) streams. The information in the endpoint companion descriptor must be stored with the other device, config, interface, and endpoint descriptors because the host controller needs to access them quickly, and we need to install some default values if a SuperSpeed device doesn't provide an endpoint companion descriptor. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-27 19:58:14 -07:00
USB: Fix duplicate sysfs problem after device reset. Borislav Petkov reports issues with duplicate sysfs endpoint files after a resume from a hibernate. It turns out that the code to support alternate settings under xHCI has issues when a device with a non-default alternate setting is reset during the hibernate: [ 427.681810] Restarting tasks ... [ 427.681995] hub 1-0:1.0: state 7 ports 6 chg 0004 evt 0000 [ 427.682019] usb usb3: usb resume [ 427.682030] ohci_hcd 0000:00:12.0: wakeup root hub [ 427.682191] hub 1-0:1.0: port 2, status 0501, change 0000, 480 Mb/s [ 427.682205] usb 1-2: usb wakeup-resume [ 427.682226] usb 1-2: finish reset-resume [ 427.682886] done. [ 427.734658] ehci_hcd 0000:00:12.2: port 2 high speed [ 427.734663] ehci_hcd 0000:00:12.2: GetStatus port 2 status 001005 POWER sig=se0 PE CONNECT [ 427.746682] hub 3-0:1.0: hub_reset_resume [ 427.746693] hub 3-0:1.0: trying to enable port power on non-switchable hub [ 427.786715] usb 1-2: reset high speed USB device using ehci_hcd and address 2 [ 427.839653] ehci_hcd 0000:00:12.2: port 2 high speed [ 427.839666] ehci_hcd 0000:00:12.2: GetStatus port 2 status 001005 POWER sig=se0 PE CONNECT [ 427.847717] ohci_hcd 0000:00:12.0: GetStatus roothub.portstatus [1] = 0x00010100 CSC PPS [ 427.915497] hub 1-2:1.0: remove_intf_ep_devs: if: ffff88022f9e8800 ->ep_devs_created: 1 [ 427.915774] hub 1-2:1.0: remove_intf_ep_devs: bNumEndpoints: 1 [ 427.915934] hub 1-2:1.0: if: ffff88022f9e8800: endpoint devs removed. [ 427.916158] hub 1-2:1.0: create_intf_ep_devs: if: ffff88022f9e8800 ->ep_devs_created: 0, ->unregistering: 0 [ 427.916434] hub 1-2:1.0: create_intf_ep_devs: bNumEndpoints: 1 [ 427.916609] ep_81: create, parent hub [ 427.916632] ------------[ cut here ]------------ [ 427.916644] WARNING: at fs/sysfs/dir.c:477 sysfs_add_one+0x82/0x96() [ 427.916649] Hardware name: System Product Name [ 427.916653] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:12.2/usb1/1-2/1-2:1.0/ep_81' [ 427.916658] Modules linked in: binfmt_misc kvm_amd kvm powernow_k8 cpufreq_ondemand cpufreq_powersave cpufreq_userspace freq_table cpufreq_conservative ipv6 vfat fat +8250_pnp 8250 pcspkr ohci_hcd serial_core k10temp edac_core [ 427.916694] Pid: 278, comm: khubd Not tainted 2.6.33-rc2-00187-g08d869a-dirty #13 [ 427.916699] Call Trace: The problem is caused by a mismatch between the USB core's view of the device state and the USB device and xHCI host's view of the device state. After the device reset and re-configuration, the device and the xHCI host think they are using alternate setting 0 of all interfaces. However, the USB core keeps track of the old state, which may include non-zero alternate settings. It uses intf->cur_altsetting to keep the endpoint sysfs files for the old state across the reset. The bandwidth allocation functions need to know what the xHCI host thinks the current alternate settings are, so original patch set intf->cur_altsetting to the alternate setting 0. This caused duplicate endpoint files to be created. The solution is to not set intf->cur_altsetting before calling usb_set_interface() in usb_reset_and_verify_device(). Instead, we add a new flag to struct usb_interface to tell usb_hcd_alloc_bandwidth() to use alternate setting 0 as the currently installed alternate setting. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Tested-by: Borislav Petkov <petkovbb@googlemail.com> Cc: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-01-06 10:16:51 -08:00
2010-02-12 12:21:11 +01:00
USB: make usbdevices export their device nodes instead of using a separate class o The "real" usb-devices export now a device node which can populate /dev/bus/usb. o The usb_device class is optional now and can be disabled in the kernel config. Major/minor of the "real" devices and class devices are the same. o The environment of the usb-device event contains DEVNUM and BUSNUM to help udev and get rid of the ugly udev rule we need for the class devices. o The usb-devices and usb-interfaces share the same bus, so I used the new "struct device_type" to let these devices identify themselves. This also removes the current logic of using a magic platform-pointer. The name of the device_type is also added to the environment which makes it easier to distinguish the different kinds of devices on the same subsystem. It looks like this: add@/devices/pci0000:00/0000:00:1d.1/usb2/2-1 ACTION=add DEVPATH=/devices/pci0000:00/0000:00:1d.1/usb2/2-1 SUBSYSTEM=usb SEQNUM=1533 MAJOR=189 MINOR=131 DEVTYPE=usb_device PRODUCT=46d/c03e/2000 TYPE=0/0/0 BUSNUM=002 DEVNUM=004 This udev rule works as a replacement for usb_device class devices: SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", \ NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0644" Updated patch, which needs the device_type patches in Greg's tree. I also got a bugzilla assigned for this. :) https://bugzilla.novell.com/show_bug.cgi?id=250659 Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-03-13 15:59:31 +01:00
USB: make usbdevices export their device nodes instead of using a separate class o The "real" usb-devices export now a device node which can populate /dev/bus/usb. o The usb_device class is optional now and can be disabled in the kernel config. Major/minor of the "real" devices and class devices are the same. o The environment of the usb-device event contains DEVNUM and BUSNUM to help udev and get rid of the ugly udev rule we need for the class devices. o The usb-devices and usb-interfaces share the same bus, so I used the new "struct device_type" to let these devices identify themselves. This also removes the current logic of using a magic platform-pointer. The name of the device_type is also added to the environment which makes it easier to distinguish the different kinds of devices on the same subsystem. It looks like this: add@/devices/pci0000:00/0000:00:1d.1/usb2/2-1 ACTION=add DEVPATH=/devices/pci0000:00/0000:00:1d.1/usb2/2-1 SUBSYSTEM=usb SEQNUM=1533 MAJOR=189 MINOR=131 DEVTYPE=usb_device PRODUCT=46d/c03e/2000 TYPE=0/0/0 BUSNUM=002 DEVNUM=004 This udev rule works as a replacement for usb_device class devices: SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", \ NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0644" Updated patch, which needs the device_type patches in Greg's tree. I also got a bugzilla assigned for this. :) https://bugzilla.novell.com/show_bug.cgi?id=250659 Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-03-13 15:59:31 +01:00
[PATCH] USB: Consider power budget when choosing configuration This patch (as609) changes the way we keep track of power budgeting for USB hubs and devices, and it updates the choose_configuration routine to take this information into account. (This is something we should have been doing all along.) A new field in struct usb_device holds the amount of bus current available from the upstream port, and the usb_hub structure keeps track of the current available for each downstream port. Two new rules for configuration selection are added: Don't select a self-powered configuration when only bus power is available. Don't select a configuration requiring more bus power than is available. However the first rule is #if-ed out, because I found that the internal hub in my HP USB keyboard claims that its only configuration is self-powered. The rule would prevent the configuration from being chosen, leaving the hub & keyboard unconfigured. Since similar descriptor errors may turn out to be fairly common, it seemed wise not to include a rule that would break automatic configuration unnecessarily for such devices. The second rule may also trigger unnecessarily, although this should be less common. More likely it will annoy people by sometimes failing to accept configurations that should never have been chosen in the first place. The patch also changes usbcore's reaction when no configuration is suitable. Instead of raising an error and rejecting the device, now the core will simply leave the device unconfigured. People can always work around such problems by installing configurations manually through sysfs. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-11-23 12:03:12 -05:00
USB: make usbdevices export their device nodes instead of using a separate class o The "real" usb-devices export now a device node which can populate /dev/bus/usb. o The usb_device class is optional now and can be disabled in the kernel config. Major/minor of the "real" devices and class devices are the same. o The environment of the usb-device event contains DEVNUM and BUSNUM to help udev and get rid of the ugly udev rule we need for the class devices. o The usb-devices and usb-interfaces share the same bus, so I used the new "struct device_type" to let these devices identify themselves. This also removes the current logic of using a magic platform-pointer. The name of the device_type is also added to the environment which makes it easier to distinguish the different kinds of devices on the same subsystem. It looks like this: add@/devices/pci0000:00/0000:00:1d.1/usb2/2-1 ACTION=add DEVPATH=/devices/pci0000:00/0000:00:1d.1/usb2/2-1 SUBSYSTEM=usb SEQNUM=1533 MAJOR=189 MINOR=131 DEVTYPE=usb_device PRODUCT=46d/c03e/2000 TYPE=0/0/0 BUSNUM=002 DEVNUM=004 This udev rule works as a replacement for usb_device class devices: SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", \ NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0644" Updated patch, which needs the device_type patches in Greg's tree. I also got a bugzilla assigned for this. :) https://bugzilla.novell.com/show_bug.cgi?id=250659 Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-03-13 15:59:31 +01:00
USB: make usbdevices export their device nodes instead of using a separate class o The "real" usb-devices export now a device node which can populate /dev/bus/usb. o The usb_device class is optional now and can be disabled in the kernel config. Major/minor of the "real" devices and class devices are the same. o The environment of the usb-device event contains DEVNUM and BUSNUM to help udev and get rid of the ugly udev rule we need for the class devices. o The usb-devices and usb-interfaces share the same bus, so I used the new "struct device_type" to let these devices identify themselves. This also removes the current logic of using a magic platform-pointer. The name of the device_type is also added to the environment which makes it easier to distinguish the different kinds of devices on the same subsystem. It looks like this: add@/devices/pci0000:00/0000:00:1d.1/usb2/2-1 ACTION=add DEVPATH=/devices/pci0000:00/0000:00:1d.1/usb2/2-1 SUBSYSTEM=usb SEQNUM=1533 MAJOR=189 MINOR=131 DEVTYPE=usb_device PRODUCT=46d/c03e/2000 TYPE=0/0/0 BUSNUM=002 DEVNUM=004 This udev rule works as a replacement for usb_device class devices: SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", \ NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0644" Updated patch, which needs the device_type patches in Greg's tree. I also got a bugzilla assigned for this. :) https://bugzilla.novell.com/show_bug.cgi?id=250659 Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-03-13 15:59:31 +01:00
Driver core: create lock/unlock functions for struct device In the future, we are going to be changing the lock type for struct device (once we get the lockdep infrastructure properly worked out) To make that changeover easier, and to possibly burry the lock in a different part of struct device, let's create some functions to lock and unlock a device so that no out-of-core code needs to be changed in the future. This patch creates the device_lock/unlock/trylock() functions, and converts all in-tree users to them. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jean Delvare <khali@linux-fr.org> Cc: Dave Young <hidave.darkstar@gmail.com> Cc: Ming Lei <tom.leiming@gmail.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Phil Carmody <ext-phil.2.carmody@nokia.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Pavel Machek <pavel@ucw.cz> Cc: Len Brown <len.brown@intel.com> Cc: Magnus Damm <damm@igel.co.jp> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: David Brownell <dbrownell@users.sourceforge.net> Cc: Vegard Nossum <vegard.nossum@gmail.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Alex Chiang <achiang@hp.com> Cc: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrew Patterson <andrew.patterson@hp.com> Cc: Yu Zhao <yu.zhao@intel.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Samuel Ortiz <sameo@linux.intel.com> Cc: Wolfram Sang <w.sang@pengutronix.de> Cc: CHENG Renquan <rqcheng@smu.edu.sg> Cc: Oliver Neukum <oliver@neukum.org> Cc: Frans Pop <elendil@planet.nl> Cc: David Vrabel <david.vrabel@csr.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-02-17 10:57:05 -08:00
USB: add reset_resume method This patch (as918) introduces a new USB driver method: reset_resume. It is called when a device needs to be reset as part of a resume procedure (whether because of a device quirk or because of the USB-Persist facility), thereby taking over a role formerly assigned to the post_reset method. As a consequence, post_reset no longer needs an argument indicating whether it is being called as part of a reset-resume. This separation of functions makes the code clearer. In addition, the pre_reset and post_reset method return types are changed; they now must return an error code. The return value is unused at present, but at some later time we may unbind drivers and re-probe if they encounter an error during reset handling. The existing pre_reset and post_reset methods in the usbhid, usb-storage, and hub drivers are updated to match the new requirements. For usbhid the post_reset routine is also used for reset_resume (duplicate method pointers); for the other drivers a new reset_resume routine is added. The change to hub.c looks bigger than it really is, because mark_children_for_reset_resume() gets moved down next to the new hub_reset_resume() routine. A minor change to usb-storage makes the usb_stor_report_bus_reset() routine acquire the host lock instead of requiring the caller to hold it already. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Jiri Kosina <jkosina@suse.cz> CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-30 15:38:16 -04:00
USB: add reset_resume method This patch (as918) introduces a new USB driver method: reset_resume. It is called when a device needs to be reset as part of a resume procedure (whether because of a device quirk or because of the USB-Persist facility), thereby taking over a role formerly assigned to the post_reset method. As a consequence, post_reset no longer needs an argument indicating whether it is being called as part of a reset-resume. This separation of functions makes the code clearer. In addition, the pre_reset and post_reset method return types are changed; they now must return an error code. The return value is unused at present, but at some later time we may unbind drivers and re-probe if they encounter an error during reset handling. The existing pre_reset and post_reset methods in the usbhid, usb-storage, and hub drivers are updated to match the new requirements. For usbhid the post_reset routine is also used for reset_resume (duplicate method pointers); for the other drivers a new reset_resume routine is added. The change to hub.c looks bigger than it really is, because mark_children_for_reset_resume() gets moved down next to the new hub_reset_resume() routine. A minor change to usb-storage makes the usb_stor_report_bus_reset() routine acquire the host lock instead of requiring the caller to hold it already. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Jiri Kosina <jkosina@suse.cz> CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-30 15:38:16 -04:00
USB: add reset_resume method This patch (as918) introduces a new USB driver method: reset_resume. It is called when a device needs to be reset as part of a resume procedure (whether because of a device quirk or because of the USB-Persist facility), thereby taking over a role formerly assigned to the post_reset method. As a consequence, post_reset no longer needs an argument indicating whether it is being called as part of a reset-resume. This separation of functions makes the code clearer. In addition, the pre_reset and post_reset method return types are changed; they now must return an error code. The return value is unused at present, but at some later time we may unbind drivers and re-probe if they encounter an error during reset handling. The existing pre_reset and post_reset methods in the usbhid, usb-storage, and hub drivers are updated to match the new requirements. For usbhid the post_reset routine is also used for reset_resume (duplicate method pointers); for the other drivers a new reset_resume routine is added. The change to hub.c looks bigger than it really is, because mark_children_for_reset_resume() gets moved down next to the new hub_reset_resume() routine. A minor change to usb-storage makes the usb_stor_report_bus_reset() routine acquire the host lock instead of requiring the caller to hold it already. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Jiri Kosina <jkosina@suse.cz> CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-30 15:38:16 -04:00
2010-04-02 13:27:28 -04:00
2010-04-02 13:27:28 -04:00
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 14:55:46 +01:00
2009-06-11 08:53:20 -06:00
2009-06-11 08:53:20 -06:00
USB: Push scatter gather lists down to host controller drivers. This is the original patch I created before David Vrabel posted a better patch (http://marc.info/?l=linux-usb&m=123377477209109&w=2) that does basically the same thing. This patch will get replaced with his (modified) patch later. Allow USB device drivers that use usb_sg_init() and usb_sg_wait() to push bulk endpoint scatter gather lists down to the host controller drivers. This allows host controller drivers to more efficiently enqueue these transfers, and allows the xHCI host controller to better take advantage of USB 3.0 "bursts" for bulk endpoints. This patch currently only enables scatter gather lists for bulk endpoints. Other endpoint types that use the usb_sg_* functions will not have their scatter gather lists pushed down to the host controller. For periodic endpoints, we want each scatterlist entry to be a separate transfer. Eventually, HCDs could parse these scatter-gather lists for periodic endpoints also. For now, we use the old code and call usb_submit_urb() for each scatterlist entry. The caller of usb_sg_init() can request that all bytes in the scatter gather list be transferred by passing in a length of zero. Handle that request for a bulk endpoint under xHCI by walking the scatter gather list and calculating the length. We could let the HCD handle a zero length in this case, but I'm not sure if the core layers in between will get confused by this. Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-27 19:59:01 -07:00