Thread (8 messages) flat view 8 messages, 4 authors, 2d ago

Re: [PATCH net-next v2] ch9200: do return USB errors from control_write()

From: Sergey Shtylyov <hidden>
Date: 2026-09-21 19:59:19
Also in: linux-usb, lkml

On 9/19/26 4:21 AM, Jakub Kicinski wrote:
[...]
quoted
quoted
There is a second point about the resulting contract.  On success
usb_control_msg() returns the transferred length, so control_write() now
returns a positive value (2 for these register writes) rather than 0:

        err = usb_control_msg(dev->udev, ...);
        if (err >= 0 && err < size)
                err = -EINVAL;

Would the obvious caller-side follow-up "if (retval) return retval;" then
treat every successful 2-byte register write as a failure?  Would it be
better to normalize success to 0 in control_write(), or to check
"retval < 0" in each caller and update the callers in the same patch so
the errors being returned are actually acted upon?
   That's what the patch I linked to does...
Please fix the issues in one series or not at all.
   OK. Series against net-next, right?
We have too many patches in flight these days to be chasing people's
linked series. Too many LLM-happy "helpers".
   IMHO these 2 patches are not so heavily linked, that's why I posted
them separately... And no AI was involved, of course. :-)
Please explain how you discovered the issue and how you tested the fix.
   As I noted in the description of the patch [1], the issue was reported
by the static analyzer. For the patch [2], I saw a problem with my own eyes.
   I don't have the hardware, so no testing; there was some hope that e.g.
Matthew Garret (the driver's original submitter) could be able to test but
his email bounced...

[1] https://lore.kernel.org/all/20260914202503.52920-1-s.shtylyov@auroraos.dev/ (local)
[2] https://lore.kernel.org/all/20260915185805.38712-1-s.shtylyov@auroraos.dev/ (local)

MBR, Sergey
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