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Filename Latest commit message Latest commit date
Mathias Nyman a6a5d08170 xhci: make sure TRB is fully written before giving it to the controller
commit 576667bad341516edc4e18eb85acb0a2b4c9c9d9 upstream.

Once the command ring doorbell is rung the xHC controller will parse all
command TRBs on the command ring that have the cycle bit set properly.

If the driver just started writing the next command TRB to the ring when
hardware finished the previous TRB, then HW might fetch an incomplete TRB
as long as its cycle bit set correctly.

A command TRB is 16 bytes (128 bits) long.
Driver writes the command TRB in four 32 bit chunks, with the chunk
containing the cycle bit last. This does however not guarantee that
chunks actually get written in that order.

This was detected in stress testing when canceling URBs with several
connected USB devices.
Two consecutive "Set TR Dequeue pointer" commands got queued right
after each other, and the second one was only partially written when
the controller parsed it, causing the dequeue pointer to be set
to bogus values. This was seen as error messages:

"Mismatch between completed Set TR Deq Ptr command & xHCI internal state"

Solution is to add a write memory barrier before writing the cycle bit.

Cc: <stable@vger.kernel.org>
Tested-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210115161907.2875631-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27 11:47:51 +01:00
arch x86/mmx: Use KFPU_387 for MMX string operations 2021-01-27 11:47:49 +01:00
block bfq: Fix computation of shallow depth 2021-01-19 18:26:15 +01:00
certs
crypto crypto: asym_tpm: correct zero out potential secrets 2021-01-12 20:16:17 +01:00
Documentation x86/xen: Add xen_no_vector_callback option to test PCI INTX delivery 2021-01-27 11:47:45 +01:00
drivers xhci: make sure TRB is fully written before giving it to the controller 2021-01-27 11:47:51 +01:00
fs cifs: do not fail __smb_send_rqst if non-fatal signals are pending 2021-01-27 11:47:49 +01:00
include xen: Fix event channel callback via INTX/GSI 2021-01-27 11:47:44 +01:00
init exec: Transform exec_update_mutex into a rw_semaphore 2021-01-09 13:44:55 +01:00
ipc
kernel bpf: Fix helper bpf_map_peek_elem_proto pointing to wrong callback 2021-01-23 15:57:56 +01:00
lib lib/raid6: Let $(UNROLL) rules work with macOS userland 2021-01-19 18:26:15 +01:00
LICENSES
mm mm, slub: consider rest of partial list if acquire_slab() fails 2021-01-19 18:26:18 +01:00
net mac80211: check if atf has been disabled in __ieee80211_schedule_txq 2021-01-23 15:58:00 +01:00
samples samples: bpf: Fix lwt_len_hist reusing previous BPF map 2020-12-30 11:51:12 +01:00
scripts depmod: handle the case of /sbin/depmod without /sbin in PATH 2021-01-12 20:16:10 +01:00
security dump_common_audit_data(): fix racy accesses to ->d_name 2021-01-19 18:26:16 +01:00
sound ASoC: Intel: haswell: Add missing pm_ops 2021-01-27 11:47:42 +01:00
tools selftests: net: fib_tests: remove duplicate log test 2021-01-27 11:47:48 +01:00
usr
virt kvm: check tlbs_dirty directly 2021-01-12 20:16:22 +01:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS Documentation/llvm: add documentation on building w/ Clang/LLVM 2020-08-26 10:40:46 +02:00
Makefile Linux 5.4.92 2021-01-23 15:58:01 +01:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.