frindex is a 14 bits counter, so bits 31-14 should always be 0, and
after the commit titled "usb-ehci: frindex always is a 14 bits counter"
we rely on frindex always being a multiple of 8. I've not seen this in
practice, but theoretically a guest can write a value >= 0x4000 or a value
which is not a multiple of 8 value to frindex, this patch ensures that
things will still work when that happens.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
To answer the question in the comment removed by this patch: I think
this was needed because several places in the ehci emulation did not
check the T bit of link entries correctly and thus might have followed
invalid references. See commit 2a5ff735dc
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Not sure what the purpose of the assert() was, in any case it is bogous.
We can arrive there if transfer descriptors passed to us from the guest
failed to pass sanity checks, i.e. it is guest-triggerable. We deal
with that case by resetting the host controller. Everything is ok, no
need to throw a core dump here.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
The sofv value only ever gets a value assigned and is never used (read)
anywhere, so we can just drop it.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
frindex always is a 14 bits counter, and not a 13 bits one as we were
emulating. There are some subtle hints to this in the spec, first of all
"Table 2-12. FRINDEX - Frame Index Register" says:
"Bit 13:0 Frame Index. The value in this register increments at the end of
each time frame (e.g. micro-frame). Bits [N:3] are used for the Frame List
current index. This means that each location of the frame list is accessed
8 times (frames or micro-frames) before moving to the next index. The
following illustrates values of N based on the value of the Frame List
Size field in the USBCMD register.
USBCMD[Frame List Size] Number Elements N
00b 1024 12
01b 512 11
10b 256 10
11b Reserved"
Notice how the text talks about "Bits [N:3]" are used ..., it does
NOT say that when N == 12 (our case) the counter will wrap from 8191 to 0,
or in otherwords that it is a 13 bits counter (bits 0 - 12).
The other hint is in "Table 2-10. USBSTS USB Status Register Bit Definitions":
"Bit 3 Frame List Rollover - R/WC. The Host Controller sets this bit to a one
when the Frame List Index (see Section 2.3.4) rolls over from its maximum value
to zero. The exact value at which the rollover occurs depends on the frame
list size. For example, if the frame list size (as programmed in the Frame
List Size field of the USBCMD register) is 1024, the Frame Index Register
rolls over every time FRINDEX[13] toggles. Similarly, if the size is 512,
the Host Controller sets this bit to a one every time FRINDEX[12] toggles."
Notice how this text talks about setting bit 3 when bit 13 of frindex toggles
(when there are 1024 entries, so our case), so this indicates that frindex
has a bit 13 making it a 14 bit counter.
Besides these clear hints the real proof is in the pudding. Before this
patch I could not stream data from a USB2 webcam under Windows XP, after
this cam using a USB2 webcam under Windows XP works fine, and no regressions
with other operating systems were seen.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Looks like a cut+paste bug from ehci_detach. When the device itself is
detached from a ehci port (ehci_detach op) we have to clear the
device pointer for the companion port too. When a device gets removed
from a downstream port of a usb hub (ehci_child_detach op) the ehci port
where the usb hub is plugged in is not affected.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reorganize usb source files. Create a new hw/usb/ directory and move
all usb source code to that place. Also make filenames a bit more
descriptive. Host adapters are prefixed with "hch-" now, usb device
emulations are prefixed with "dev-". Fixup paths Makefile and include
paths to make it compile. No code changes.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Hans de Goede
Gerd Hoffmann