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!
Alan Stern