There's a new PM-related change notice for the USB 2.0 specification
called "Link Power Management" (LPM). It defines a new "L1 Suspend"
state which resembles the current (L2) suspend state, except that it
can be entered and exited much more quickly. It should thus be more
useful for runtime PM, even though it doesn't mandate reduced power
draw from VBUS.
This patch provides the relevant #defines for usbcore. Actually
implementing these mechanisms requires host silicon that can generate
new USB packets, plus hubs handling some new requests and peripherals
which understand the new packets.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as809b) moves the declaration of the hub driver's private
data structure from hub.h into the hub.c source file. Lots of other
files import hub.h; they have no need to know about the details of the
hub driver's private data.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Current Wireless USB host hardware (Intel i1480 for example) allows up
to 22 devices to connect, thus bringing up the max number of children
in the WUSB Host Controller to 22 'fake' ports. Upcoming hardware
might raise that limit.
Makes almost no difference to go to 31, as the bit arrays are
byte-aligned (plus an extra bit in general), so 22 bits fit in 4 bytes
as 31 do.
As well, the only other array that depends on USB_MAXCHILDREN is
'struct usb_hub->indicator'. By declaring it 'u8' instead of 'enum
hub_led_mode', we reduce the size of each entry from 4 bytes (in i386)
to 1, which will add as we when are doubling USB_MAXCHILDREN
(with 16 the size of that array is 64 bytes, with 31 would be 128; by
using u8 that goes down to 31 bytes).
Signed-off-by: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We don't want khubd to start interfering in the device-resume process
merely because the PORT_STATUS_C_SUSPEND feature happens to be set.
Ports need to be marked as busy while a resume is taking place.
In addition, so long as ports are marked as busy, khubd won't be able to
clear their various status-change features. On an interrupt-driven root
hub this could lead to an interrupt storm. Root hub IRQs should not be
re-enabled until the busy_bits value is equal to 0.
This patch (as765) fixes these two potential problems.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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>
Also has the nice benefit of making sparc alignment issues go away.
Thanks to David Miller for pointing out the problems here.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/core/hub.c | 22 ++++++++++++----------
drivers/usb/core/hub.h | 2 +-
2 files changed, 13 insertions(+), 11 deletions(-)
This adds think_time to the usb_tt struct and sets it appropriately
(measured in ns); this can help us implement better split transaction
scheduling.
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch removes the hub_set_power_budget routine, which was used by a
couple of HCDs to indicate that the root hub was running on battery power.
In its place is a new field added to struct usb_hcd, which HCDs can set
before the root hub is registered. Special-case code in the hub driver
knows to look at this field when configuring a root hub.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
