litmus-rt.git/drivers/usb/host/ehci-mem.c, branch 2010.2

USB: EHCI: defer reclamation of siTDs

2010-04-22T22:18:28+00:00

This patch (as1369) fixes a problem in ehci-hcd.  Some controllers
occasionally run into trouble when the driver reclaims siTDs too
quickly.  This can happen while streaming audio; it causes the
controller to crash.

The patch changes siTD reclamation to work the same way as iTD
reclamation: Completed siTDs are stored on a list and not reused until
at least one frame has passed.

Signed-off-by: Alan Stern 
Tested-by: Nate Case 
CC: 
Signed-off-by: Greg Kroah-Hartman

USB: EHCI: split ehci_qh into hw and sw parts

2009-09-23T13:46:29+00:00

The ehci_qh structure merged hw and sw together which is not good:
1. More and more items are being added into ehci_qh, the ehci_qh software
   part are unnecessary to be allocated in DMA qh_pool.
2. If HCD has local SRAM, the sw part will consume it too, and it won't
   bring any benefit.
3. For non-cache-coherence system, the entire ehci_qh is uncachable, actually
   we only need the hw part to be uncacheable. Spliting them will let the sw
   part to be cacheable.

Signed-off-by: Alek Du 
Cc: David Brownell 
CC: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: EHCI: slow down ITD reuse

2009-02-27T22:40:50+00:00

Currently ITDs are immediately recycled whenever their URB completes.
However, EHCI hardware can sometimes remember some ITD state.  This
means that when the ITD is reused before end-of-frame it may sometimes
cause the hardware to reference bogus state.

This patch defers reusing such ITDs by moving them into a new ehci member
cached_itd_list. ITDs resting in cached_itd_list are moved back into their
stream's free_list once scan_periodic() detects that the active frame has
elapsed.

This makes the snd_usb_us122l driver (in kernel since .28) work right
when it's hooked up through EHCI.

[ dbrownell@users.sourceforge.net: comment fixups ]

Signed-off-by: Karsten Wiese 
Tested-by: Philippe Carriere 
Tested-by: Federico Briata 
Cc: stable 
Signed-off-by: David Brownell 
Signed-off-by: Greg Kroah-Hartman

Revert "USB: EHCI cpufreq fix"

2007-08-21T06:38:44+00:00

This reverts commit 196705c9bbc03540429b0f7cf9ee35c2f928a534.  It was
reported to cause a regression by Daniel Exner, and Arjan van de Ven
points out that we actually already have infrastructure in place for
setting limits on acceptable DMA latency that would be the much more
correct fix for the problem with some Broadcom EHCI controllers.

Fixed up trivial conflicts due to the changes to support big-endian host
controller descriptors in drivers/usb/host/{ehci-sched.c,ehci.h}.

Signed-off-by: Linus Torvalds

USB: ehci refcounts work on ppc7448

2007-07-12T23:29:47+00:00

Remove atomic operations on the reference counter for EHCI queue heads.
On various platforms (including ppc7448), atomic operations are unusable
with dma-coherent memory.

Signed-off-by: Steven J. Hill 
Signed-off-by: David Brownell 
Signed-off-by: Greg Kroah-Hartman

USB: EHCI support for big-endian descriptors

2007-07-12T23:29:45+00:00

This patch implements supports for EHCI controllers whose in-memory
data structures are represented in big-endian format. This is needed
(unfortunately) for the AMCC PPC440EPx SoC EHCI controller; the EHCI
spec doesn't specify little-endian format, although that's what most
other implementations use.

The guts of the patch are to introduce the hc32 type and change all
references from le32 to hc32.  All access routines are converted from
cpu_to_le32(...) to cpu_to_hc32(ehci, ...) and similar for the other
"direction".  (This is the same approach used with OHCI.)

David fixed:
	Whitespace fixes; refresh against ehci cpufreq patch; move glue
	for that PPC driver to the patch adding it; fix free symbol
	capture bugs in modified "constant" macros; and make "hc32" etc
	be "le32" unless we really need the BE options, so "sparse" can
	do some real good.

Signed-off-by: Stefan Roese 
Signed-off-by: David Brownell 
Signed-off-by: Greg Kroah-Hartman

USB: EHCI cpufreq fix

2007-07-12T23:29:45+00:00

EHCI controllers that don't cache enough microframes can get MMF errors
when CPU frequency changes occur between the start and completion of
split interrupt transactions, due to delays in reading main memory
(caused by CPU cache snoop delays).

This patch adds a cpufreq notifier to the EHCI driver that will
inactivate split interrupt transactions during frequency transitions.
It was tested on Intel ICH7 and Serverworks/Broadcom HT1000 EHCI
controllers.

Signed-off-by: Stuart Hayes 
Signed-off-by: David Brownell 
Signed-off-by: Greg Kroah-Hartman

USB: EHCI whitespace fixes (cosmetic)

2006-09-27T18:58:56+00:00

[ ... when you have an editor set to remind you of whitespace bugs ... ]

Cosmetic EHCI changes: remove end-of-line whitespace, spaces before tabs.

Signed-off-by: David Brownell 
Signed-off-by: Greg Kroah-Hartman

[PATCH] USB: kzalloc() conversion for rest of drivers/usb

2006-03-20T22:49:59+00:00

Signed-off-by: Eric Sesterhenn 
Signed-off-by: Greg Kroah-Hartman

[PATCH] USB core and HCDs: don't put_device while atomic

2006-03-20T22:49:58+00:00

This patch (as640) removes several put_device and the corresponding
get_device calls from the USB core and HCDs.  Some of the puts were done
in atomic contexts, and none of them are needed since the core now
guarantees that every endpoint will be disabled and every URB completed
before a USB device is released.

Signed-off-by: Alan Stern 
Acked-by: David Brownell 
Signed-off-by: Greg Kroah-Hartman