A recent cleanup went a bit too far and dropped clearing the cycle bit
of link TRBs, so it stays different from the rest of the ring half of
the time. Then a race occurs: if the xHC reaches such link TRB before
more commands are queued, the link's cycle bit unintentionally matches
the xHC's cycle so it follows the link and waits for further commands.
If more commands are queued before the xHC gets there, inc_enq() flips
the bit so the xHC later sees a mismatch and stops executing commands.
This function is called before suspend and 50% of times after resuming
the xHC is doomed to get stuck sooner or later. Then some Stop Endpoint
command fails to complete in 5 seconds and this shows up
xhci_hcd 0000:00:10.0: xHCI host not responding to stop endpoint command
xhci_hcd 0000:00:10.0: xHCI host controller not responding, assume dead
xhci_hcd 0000:00:10.0: HC died; cleaning up
followed by loss of all USB decives on the affected bus. That's if you
are lucky, because if Set Deq gets stuck instead, the failure is silent.
Likely responsible for kernel bug 219824. I found this while searching
for possible causes of that regression and reproduced it locally before
hearing back from the reporter. To repro, simply wait for link cycle to
become set (debugfs), then suspend, resume and wait. To accelerate the
failure I used a script which repeatedly starts and stops a UVC camera.
Some HCs get fully reinitialized on resume and they are not affected.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219824
Fixes: 36b972d4b7 ("usb: xhci: improve xhci_clear_command_ring()")
Cc: stable@vger.kernel.org
Signed-off-by: Michal Pecio <michal.pecio@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20250304113147.3322584-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When adding support for USB3-over-USB4 tunnelling detection, a check
for an Intel-specific capability was added. This capability, which
goes by ID 206, is used without any check that we are actually
dealing with an Intel host.
As it turns out, the Cadence XHCI controller *also* exposes an
extended capability numbered 206 (for unknown purposes), but of
course doesn't have the Intel-specific registers that the tunnelling
code is trying to access. Fun follows.
The core of the problems is that the tunnelling code blindly uses
vendor-specific capabilities without any check (the Intel-provided
documentation I have at hand indicates that 192-255 are indeed
vendor-specific).
Restrict the detection code to Intel HW for real, preventing any
further explosion on my (non-Intel) HW.
Cc: stable <stable@kernel.org>
Fixes: 948ce83fbb ("xhci: Add USB4 tunnel detection for USB3 devices on Intel hosts")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20250227194529.2288718-1-maz@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Raspberry Pi is a major user of those chips and they discovered a bug -
when the end of a transfer ring segment is reached, up to four TRBs can
be prefetched from the next page even if the segment ends with link TRB
and on page boundary (the chip claims to support standard 4KB pages).
It also appears that if the prefetched TRBs belong to a different ring
whose doorbell is later rung, they may be used without refreshing from
system RAM and the endpoint will stay idle if their cycle bit is stale.
Other users complain about IOMMU faults on x86 systems, unsurprisingly.
Deal with it by using existing quirk which allocates a dummy page after
each transfer ring segment. This was seen to resolve both problems. RPi
came up with a more efficient solution, shortening each segment by four
TRBs, but it complicated the driver and they ditched it for this quirk.
Also rename the quirk and add VL805 device ID macro.
Signed-off-by: Michal Pecio <michal.pecio@gmail.com>
Link: https://github.com/raspberrypi/linux/issues/4685
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=215906
CC: stable@vger.kernel.org
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20250225095927.2512358-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull driver core and debugfs updates from Greg KH:
"Here is the big set of driver core and debugfs updates for 6.14-rc1.
Included in here is a bunch of driver core, PCI, OF, and platform rust
bindings (all acked by the different subsystem maintainers), hence the
merge conflict with the rust tree, and some driver core api updates to
mark things as const, which will also require some fixups due to new
stuff coming in through other trees in this merge window.
There are also a bunch of debugfs updates from Al, and there is at
least one user that does have a regression with these, but Al is
working on tracking down the fix for it. In my use (and everyone
else's linux-next use), it does not seem like a big issue at the
moment.
Here's a short list of the things in here:
- driver core rust bindings for PCI, platform, OF, and some i/o
functions.
We are almost at the "write a real driver in rust" stage now,
depending on what you want to do.
- misc device rust bindings and a sample driver to show how to use
them
- debugfs cleanups in the fs as well as the users of the fs api for
places where drivers got it wrong or were unnecessarily doing
things in complex ways.
- driver core const work, making more of the api take const * for
different parameters to make the rust bindings easier overall.
- other small fixes and updates
All of these have been in linux-next with all of the aforementioned
merge conflicts, and the one debugfs issue, which looks to be resolved
"soon""
* tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (95 commits)
rust: device: Use as_char_ptr() to avoid explicit cast
rust: device: Replace CString with CStr in property_present()
devcoredump: Constify 'struct bin_attribute'
devcoredump: Define 'struct bin_attribute' through macro
rust: device: Add property_present()
saner replacement for debugfs_rename()
orangefs-debugfs: don't mess with ->d_name
octeontx2: don't mess with ->d_parent or ->d_parent->d_name
arm_scmi: don't mess with ->d_parent->d_name
slub: don't mess with ->d_name
sof-client-ipc-flood-test: don't mess with ->d_name
qat: don't mess with ->d_name
xhci: don't mess with ->d_iname
mtu3: don't mess wiht ->d_iname
greybus/camera - stop messing with ->d_iname
mediatek: stop messing with ->d_iname
netdevsim: don't embed file_operations into your structs
b43legacy: make use of debugfs_get_aux()
b43: stop embedding struct file_operations into their objects
carl9170: stop embedding file_operations into their objects
...
After commit c141ecc3ce ("of: Warn when of_property_read_bool() is
used on non-boolean properties") was added, the following warning is
observed for the Tegra XHCI driver ...
OF: /bus@0/usb@3610000: Read of boolean property 'power-domains' with
a value.
Previously, of_property_read_bool() was used to determine if a property
was present but has now been replaced by of_property_present(). The
warning is meant to prevent new users but this user existed before the
change was made. Fix this by updating the Tegra XHCI driver to use
of_property_present() function to determine if the 'power-domains'
property is present.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20250116153829.477360-1-jonathanh@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Replace ternary (condition ? "enable" : "disable") syntax with helpers
from string_choices.h because:
1. Simple function call with one argument is easier to read. Ternary
operator has three arguments and with wrapping might lead to quite
long code.
2. Is slightly shorter thus also easier to read.
3. It brings uniformity in the text - same string.
4. Allows deduping by the linker, which results in a smaller binary
file.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20250114-str-enable-disable-usb-v1-2-c8405df47c19@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When inserting a USB device, examining hcd->rsrc_start can be
helpful in identifying which hcd is mounted, as the physical
address represented here is typically unique.
The following code snippet demonstrates this:
struct usb_hcd *hcd = bus_to_hcd(udev->bus);
unsigned long long usb_hcd_addr = (unsigned long long)hcd->rsrc_start;
However, this approach has limitations now. For USB hosts with an
MMIO interface, the effectiveness of this method is restricted to
USB 2.0.
Because commit 3429e91a66 ("usb: host: xhci: add platform driver
support") assigned res->start to hcd->rsrc_start. But
shared_hcd->rsrc_start remains unassigned, which is also necessary
in certain scenarios.
Fixes: 3429e91a66 ("usb: host: xhci: add platform driver support")
Co-developed-by: Xu Rao <raoxu@uniontech.com>
Signed-off-by: Xu Rao <raoxu@uniontech.com>
Signed-off-by: WangYuli <wangyuli@uniontech.com>
Link: https://lore.kernel.org/r/186B9F56972457B4+20250107133854.172309-1-wangyuli@uniontech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a command is queued to the final usable TRB of a ring segment, the
enqueue pointer is advanced to the subsequent link TRB and no further.
If the command is later aborted, when the abort completion is handled
the dequeue pointer is advanced to the first TRB of the next segment.
If no further commands are queued, xhci_handle_stopped_cmd_ring() sees
the ring pointers unequal and assumes that there is a pending command,
so it calls xhci_mod_cmd_timer() which crashes if cur_cmd was NULL.
Don't attempt timer setup if cur_cmd is NULL. The subsequent doorbell
ring likely is unnecessary too, but it's harmless. Leave it alone.
This is probably Bug 219532, but no confirmation has been received.
The issue has been independently reproduced and confirmed fixed using
a USB MCU programmed to NAK the Status stage of SET_ADDRESS forever.
Everything continued working normally after several prevented crashes.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219532
Fixes: c311e391a7 ("xhci: rework command timeout and cancellation,")
CC: stable@vger.kernel.org
Signed-off-by: Michal Pecio <michal.pecio@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20241227120142.1035206-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Improve dbc transfer rate performance by copying the received data to
the tty buffer directly in the request complete callback function if
possible.
Only defer it in case there is already pending deferred work, tty is
throttled, or we fail copy the data to the tty buffer
The request complete callback is already called by a workqueue.
This is part 3/3 of a dbc performance improvement series that roughly
triples dbc performace when using adb push and pull over dbc.
Max/min push rate after patches is 210/118 MB/s, pull rate 171/133 MB/s,
tested with large files (300MB-9GB) by Łukasz Bartosik
Cc: Łukasz Bartosik <ukaszb@chromium.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20241227120142.1035206-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Queue event polling work with 0 delay in case there are pending transfers
queued up. This is part 2 of a 3 part series that roughly triples dbc
performace when using adb push and pull over dbc.
Max/min push rate after patches is 210/118 MB/s, pull rate 171/133 MB/s,
tested with large files (300MB-9GB) by Łukasz Bartosik
First performance improvement patch was commit 31128e7492
("xhci: dbc: add dbgtty request to end of list once it completes")
Cc: Łukasz Bartosik <ukaszb@chromium.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20241227120142.1035206-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the current USB request was aborted, the spi thread would not respond
to any further requests. This is because the "curr_urb" pointer would
not become NULL, so no further requests would be taken off the queue.
The solution here is to set the "urb_done" flag, as this will cause the
correct handling of the URB. Also clear interrupts that should only be
expected if an URB is in progress.
Fixes: 2d53139f31 ("Add support for using a MAX3421E chip as a host driver.")
Cc: stable <stable@kernel.org>
Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Link: https://lore.kernel.org/r/20241124221430.1106080-1-mark.tomlinson@alliedtelesis.co.nz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
