[Linux-kernel-mentees] [RESEND PATCH v3] net: usb: usbnet: update __usbnet_{read|write}_cmd() to use new API

Jakub Kicinski kuba at kernel.org
Thu Nov 5 00:24:44 UTC 2020

On Mon,  2 Nov 2020 23:09:46 +0530 Anant Thazhemadam wrote:
> Currently, __usbnet_{read|write}_cmd() use usb_control_msg().
> However, this could lead to potential partial reads/writes being
> considered valid, and since most of the callers of
> usbnet_{read|write}_cmd() don't take partial reads/writes into account
> (only checking for negative error number is done), and this can lead to
> issues.
> However, the new usb_control_msg_{send|recv}() APIs don't allow partial
> reads and writes.
> Using the new APIs also relaxes the return value checking that must
> be done after usbnet_{read|write}_cmd() is called.
> Signed-off-by: Anant Thazhemadam <anant.thazhemadam at gmail.com>

So you're changing the semantics without updating the callers?

I'm confused. 

Is this supposed to be applied to some tree which already has the
callers fixed?

At a quick scan at least drivers/net/usb/plusb.c* would get confused 
as it compares the return value to zero and 0 used to mean "nothing
transferred", now it means "all good", no? 

* I haven't looked at all the other callers

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