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From:   "Chang, Junxiao" <junxiao.chang@intel.com>
To:     Jakub Kicinski <kuba@kernel.org>
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Subject: RE: [PATCH net-next 1/2] net: stmmac: fix unsafe MTL DMA macro
Thread-Topic: [PATCH net-next 1/2] net: stmmac: fix unsafe MTL DMA macro
Thread-Index: AQHY5UQrIcPqwyKm2kGMfbK0lW2Bca4egg+AgAACBNA=
Date:   Tue, 25 Oct 2022 04:58:12 +0000
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References: <20221021114711.1610797-1-junxiao.chang@intel.com>
 <20221024210019.551e64ae@kernel.org>
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Thank you for reviewing it. There is no real issue if this macro only be us=
ed in stmmac driver and parameter is not function or "i++".

I will squash these two patches.

Regards,
Junxiao

-----Original Message-----
From: Jakub Kicinski <kuba@kernel.org>=20
Sent: Tuesday, October 25, 2022 12:00 PM
To: Chang, Junxiao <junxiao.chang@intel.com>
Cc: peppe.cavallaro@st.com; alexandre.torgue@foss.st.com; joabreu@synopsys.=
com; davem@davemloft.net; edumazet@google.com; pabeni@redhat.com; mcoquelin=
.stm32@gmail.com; Joao.Pinto@synopsys.com; netdev@vger.kernel.org; linux-st=
m32@st-md-mailman.stormreply.com; linux-arm-kernel@lists.infradead.org; lin=
ux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next 1/2] net: stmmac: fix unsafe MTL DMA macro

On Fri, 21 Oct 2022 19:47:10 +0800 Junxiao Chang wrote:
> Macro like "#define abc(x) (x, x)" is unsafe which might introduce=20
> side effects. Each MTL RxQ DMA channel mask is 4 bits, so using (0xf=20
> << chan) instead of GENMASK(x + 3, x) to avoid unsafe macro.
>=20
> Fixes: d43042f4da3e ("net: stmmac: mapping mtl rx to dma channel")

You need to point out an existing usage where this is causing problems, oth=
erwise this is not a fix.

And squash the two patches together, it's going to be easier to review.