Re: [PATCH] thunderbolt: stream: Make read return framing error to the userspace

[Ivy Lopez]

On Mon, Sep 21, 2026 at 11:19 AM UTC, Mika Westerberg wrote:
> +                     if (!nbytes) {
> +                             pr_warn("corrupted frame received, flags %#x\n",
> +                                     sf->frame.flags);
> +                             tbstream_dev_consume_rx(sdev);
> +                             ret = -EIO;
> +                     }
> +                     break;

One question: EPOLLIN is set unconditionally in the rx callback
regardless of frame flags, and tbstream_dev_fops_poll() only checks
tbstream_ring_available() (pure ring depth), never frame flags.
EPOLLERR is used elsewhere in this file but only for device-level
invalidity, not per-frame corruption. So userspace still has no way
to learn a corrupted frame is queued via poll() before calling
read() and getting -EIO. I'm just wondering, is this intentional,
or worth a follow-up?

Also, fwiw, this doesn't apply cleanly against current usb-next for
me, git apply fails on the rx_callback hunk. Looks like it's against
a tree predating the busy-polling changes.

Not a blocker either way.

Reviewed-by: Ivy Lopez <skunkolee@xxxxxxxxx>