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)
In my quest to try and figure out why test 14 (control write) doesn't
work with my EZ-USB board, I noticed that sometimes testusb reported
no error even though the kernel log complained "byte 0 is 0 not 2" etc.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as693b) makes the usbtest driver report errors in the
isochronous bulk transfer tests instead of always returning 0. As an
arbitrary cutoff, an error is returned if more than 10% of the packet
transfers fail. It also stops a test immediately upon receiving an URB
submission error.
For a test harness, it's especially important to report when errors occur!
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
ctrl_complete functions acquires ctx->lock and tries to unlink
all queued urbs in case of errors through usb_unlink_urb func.
In its turn usb_unlink_urb calls, through the hcd driver,
usb_hcd_giveback_urb which calls ctrl_complete again. At this
time, ctx->lock is already taken by the same function.
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Previously, scatterlist tests didn't write patterned data. Given how many
corner cases are addresed by them, this was a significant gap in Linux-USB
test coverage. Moreover, when peripherals checked for correct data patterns,
false error reports would drown out the true ones.
This adds the pattern on the way OUT from the host, so scatterlist tests can
now be used to uncover bugs like host TX or peripheral RX paths failing for
back-to-back short packets. It's easy enough to get an error there with at
least one of the {DMA,PIO}{RX,TX} code paths, or run into hardware races
that need to be defended against.
Note this patch doesn't add checking for correct data patterns on the way
IN from peripherals, just a FIXME for later.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This lets us remove a lot of code in the drivers that were all checking
the same thing. It also found some bugs in a few of the drivers, which
has been fixed up.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch uses sg_set_buf/sg_init_one in some places where it was
duplicated.
Signed-off-by: David Hardeman <david@2gen.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Greg KH <greg@kroah.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch (as582) adds a missing transfer_flags setting to the usbtest
driver.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This updates the handling of power state for USB interfaces.
- Formalizes an existing invariant: interface "power state" is a boolean:
ON when I/O is allowed, and FREEZE otherwise. It does so by defining
some inlined helpers, then using them.
- Adds a useful invariant: the only interfaces marked active are those
bound to non-suspended drivers. Later patches build on this invariant.
- Simplifies the interface driver API (and removes some error paths) by
removing the requirement that they record power state changes during
suspend and resume callbacks. Now usbcore does that.
A few drivers were simplified to address that last change.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/core/hub.c | 33 +++++++++------------
drivers/usb/core/message.c | 1
drivers/usb/core/usb.c | 65 +++++++++++++++++++++++++++++++++----------
drivers/usb/core/usb.h | 18 +++++++++++
drivers/usb/input/hid-core.c | 2 -
drivers/usb/misc/usbtest.c | 10 ------
drivers/usb/net/pegasus.c | 2 -
drivers/usb/net/usbnet.c | 2 -
8 files changed, 85 insertions(+), 48 deletions(-)
29 July 2005, Cambridge, MA:
This afternoon Alan Stern submitted a patch to remove the URB_ASYNC_UNLINK
flag from the Linux kernel. Mr. Stern explained, "This flag is a relic
from an earlier, less-well-designed system. For over a year it hasn't
been used for anything other than printing warning messages."
An anonymous spokesman for the Linux kernel development community
commented, "This is exactly the sort of thing we see happening all the
time. As the kernel evolves, support for old techniques and old code can
be jettisoned and replaced by newer, better approaches. Proprietary
operating systems do not have the freedom or flexibility to change so
quickly."
Mr. Stern, a staff member at Harvard University's Rowland Institute who
works on Linux only as a hobby, noted that the patch (labelled as548) did
not update two files, keyspan.c and option.c, in the USB drivers' "serial"
subdirectory. "Those files need more extensive changes," he remarked.
"They examine the status field of several URBs at times when they're not
supposed to. That will need to be fixed before the URB_ASYNC_UNLINK flag
is removed."
Greg Kroah-Hartman, the kernel maintainer responsible for overseeing all
of Linux's USB drivers, did not respond to our inquiries or return our
calls. His only comment was "Applied, thanks."
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds type-checking to pm_message_t, so that people can't confuse it
with int or u32. It also allows us to fix "disk yoyo" during suspend (disk
spinning down/up/down).
[We've tried that before; since that cpufreq problems were fixed and I've
tried make allyes config and fixed resulting damage.]
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Alexander Nyberg <alexn@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Updates to "usbtest" driver:
* Improve some diagnostics. One path that never generated diagnostics
before should now generate two ... unless you hit a GCC bug that
all my compilers seem to have, go figure.
* Add suspend/resume support, so this behaves when the Linux host
being used for testing suspends.
* Don't test the "zero byte ep0 read" case unless real-world relevance
for the testing is is irrelevant.
Signed-off-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!
David Howells