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Date: Fri, 15 Dec 2023 17:32:27 +0100
From: Johan Hovold <johan@kernel.org>
To: Francesco Dolcini <francesco@dolcini.it>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jirislaby@kernel.org>, linux-bluetooth@vger.kernel.org,
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	Francesco Dolcini <francesco.dolcini@toradex.com>,
	Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
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	Lee Jones <lee@kernel.org>, Jakub Kicinski <kuba@kernel.org>,
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	Benson Leung <bleung@chromium.org>,
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Subject: Re: [PATCH v1] treewide, serdev: change receive_buf() return type to
 size_t
Message-ID: <ZXx_m1R0x7omubxE@hovoldconsulting.com>
References: <20231214170146.641783-1-francesco@dolcini.it>
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 <ZXxbx+laQk35W56U@francesco-nb.int.toradex.com>
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On Fri, Dec 15, 2023 at 02:59:35PM +0100, Francesco Dolcini wrote:
> On Fri, Dec 15, 2023 at 02:51:09PM +0100, Johan Hovold wrote:
> > On Thu, Dec 14, 2023 at 06:01:46PM +0100, Francesco Dolcini wrote:
> > > From: Francesco Dolcini <francesco.dolcini@toradex.com>
> > > 
> > > receive_buf() is called from ttyport_receive_buf() that expects values
> > > ">= 0" from serdev_controller_receive_buf(), change its return type from
> > > ssize_t to size_t.

> > >  drivers/bluetooth/btmtkuart.c              |  4 ++--
> > >  drivers/bluetooth/btnxpuart.c              |  4 ++--

> > > -static ssize_t btnxpuart_receive_buf(struct serdev_device *serdev,
> > > -				     const u8 *data, size_t count)
> > > +static size_t btnxpuart_receive_buf(struct serdev_device *serdev,
> > > +				    const u8 *data, size_t count)
> > >  {
> > >  	struct btnxpuart_dev *nxpdev = serdev_device_get_drvdata(serdev);
> > 
> > A quick check of just the first two functions here shows that they can
> > return negative values.
> 
> This is already fixed. Patches are in next.
> 
> There were 3 buggy user of this API.
>  - 1 patch was merged a few days ago in mainline
>  - 2 patches are in next, the maintainer decided to wait for the next merge window
> 
> commit 687d2de93b11 ("Bluetooth: btmtkuart: fix recv_buf() return value")
> commit 7954bbcdd7ea ("Bluetooth: btnxpuart: fix recv_buf() return value")
> commit c8820c92caf0 ("platform/surface: aggregator: fix recv_buf() return value")

Then why was that not mentioned in the patch (e.g. below the --- line)?

You are certainly not making it easy for reviewers, but good to see that
you thought about this, and I see now when reviewing the mail archives
that those bugs were the reason for this patch in the first place.

Johan