kernel/git/next/linux-next.git/drivers/thunderbolt/stream.c, branch master

Merge branch 'next' of https://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt.git

2026-09-14T14:22:11+00:00

thunderbolt: stream: Check the Rx ring before task starts sleeping

2026-09-14T08:53:46+00:00

In interrupt mode when tb_ring_poll_complete() is called it is possible that a frame was completed right before the ring interrupt was unmasked in which case there will be no interrupt and the task starts sleeping. Avoid this and check if there is anything completed prior putting the task to sleep. The same can happen with poll() so check the ring there too before reporting that there is nothing to read. Assisted-by: LLM Signed-off-by: Mika Westerberg

thunderbolt: stream: Do not hold the lock while busy polling

2026-09-14T08:53:45+00:00

When in busy poll mode with a reader and writer, and there is nothing completed on the rings both sides keep taking and releasing the lock from each other and this can cause stalls. Avoid this by calling the new API function tb_ring_poll_pending() that only returns true if there is anything available in which case they can take the lock and know there is now work to do. Reported-by: Alan Borzeszkowski Assisted-by: LLM Signed-off-by: Mika Westerberg

thunderbolt: stream: Use polling with RX ring

2026-09-10T05:08:33+00:00

The ring API already supports polling so that once there is anything in the RX ring, it will mask the ring interrupt and call the ->start_poll callback. This is the same mechanism that the USB4/Thunderbolt networking driver already uses. We can do the same for the USB4STREAM driver and poll any RX frames while they are available, until we re-enable the ring interrupt again. This provides better latency when the stream is in "normal" (non-busy-polling) mode. Assisted-by: LLM Signed-off-by: Mika Westerberg

treewide: refresh kmalloc_obj() conversions

2026-09-05T04:37:00+00:00

This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook

Merge tag 'thunderbolt-for-v7.3-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt into usb-next

2026-08-19T08:01:59+00:00

Mika writes: thunderbolt: Changes for v7.3 merge window This includes following USB4/Thunderbolt changes for the v7.3 merge window: - Assert Downstream Port Reset for Thunderbolt 3 devices during shutdown to avoid unnecessary delays over warm reset. - Tidy up Thunderbolt service ->probe callbacks. - USB4STREAM improvements. - AMD host interface quirk to fix Tx ring hang on teardown of a DMA tunnel. - Minor fixes and cleanups. All these have been in linux-next with no reported issues. * tag 'thunderbolt-for-v7.3-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt: thunderbolt: Clamp DMA tunnel credits to what a hop register can hold thunderbolt: Use min() for the DMA path credit cap thunderbolt: debugfs: Replace get_zeroed_page() with kzalloc() thunderbolt: Add quirk to reset host interface on DMA path teardown for AMD USB4 routers thunderbolt: stream: Add support for busy polling thunderbolt: Make interrupt optional for rings thunderbolt: stream: Support IOCB_NOWAIT in non-blocking I/O as well thunderbolt: stream: Fix possible short reads/writes thunderbolt: stream: Restore consumer if copying from iter fails thunderbolt: Remove redundant dev_err_probe() docs: admin-guide: thunderbolt: Fix sentence structure thunderbolt: xdomain: Notify peers after enumeration thunderbolt: Drop comma after device id array terminator thunderbolt: Assert that a service driver has a probe callback thunderbolt: Stop passing matched device ID to .probe() thunderbolt: Assert downstream port reset on shutdown

thunderbolt: stream: Add support for busy polling

2026-08-05T03:53:57+00:00

Using interrupts and scheduling workers increase latency so latency critical applications may want to avoid that. Make this possible in USB4STREAM by adding a new ConfigFS attribute: busy_poll that, when activated switches the rings to polling mode. The cost for lower latency is that this burns more CPU cycles and things like poll(2) cannot be used. Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Mika Westerberg

thunderbolt: stream: Support IOCB_NOWAIT in non-blocking I/O as well

2026-08-05T03:53:57+00:00

For read_iter/write_iter() it is also possible to pass IOCB_NOWAIT with the kiocb to indicate non-blocking read/write. For instance io_uring does this. So take this into account on read and write paths. Signed-off-by: Mika Westerberg

thunderbolt: stream: Fix possible short reads/writes

2026-08-05T03:53:57+00:00

Since copy_page_{to|from}_iter() advances the iterator and makes iov_iter_count() reflect the remaining bytes, subtracting nbytes from it makes it count it twice resulting in possible short reads/writes on a read/write spanning multiple frames. Fix this by using iov_iter_count() directly. Fixes: 6db21d817b43 ("thunderbolt: Add support for USB4STREAM") Signed-off-by: Mika Westerberg

thunderbolt: stream: Restore consumer if copying from iter fails

2026-08-05T03:53:57+00:00

In tbstream_dev_alloc_tx() if copying data from iterator fails we leave the consumer pointer as is wasting one entry in the ring. Fix this by restoring the consumer back in case of failure. Fixes: 6db21d817b43 ("thunderbolt: Add support for USB4STREAM") Signed-off-by: Mika Westerberg