Re: [PATCH v5] net: ethernet: add driver for Aurora VLSI NB8800 Ethernet controller

From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: "Måns Rullgård" <mans@mansr.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	netdev <netdev@vger.kernel.org>,
	slash.tmp@free.fr
Subject: Re: [PATCH v5] net: ethernet: add driver for Aurora VLSI NB8800 Ethernet controller
Date: Wed, 11 Nov 2015 00:40:53 +0200	[thread overview]
Message-ID: <CAHp75VfsswYAvkkkHuaEvkTAgZhoGZQ1oQ_R9BwZgyZ3xRVDeg@mail.gmail.com> (raw)
In-Reply-To: <yw1xr3jxpjoy.fsf@unicorn.mansr.com>

On Wed, Nov 11, 2015 at 12:34 AM, Måns Rullgård <mans@mansr.com> wrote:
> Andy Shevchenko <andy.shevchenko@gmail.com> writes:
>
>>> +static inline void nb8800_maskb(struct nb8800_priv *priv, int reg,
>>> +                               u32 mask, u32 val)
>>> +{
>>> +       u32 old = nb8800_readb(priv, reg);
>>> +       u32 new = (old & ~mask) | val;
>>
>> Shoudn't be "… | (val & mask);" ?
>
> No, it's meant to replace the bits in mask with the corresponding bits
> from val.

But you unconditionally use entire val value which might bring bits
outside of mask.

>> Block comments usually
>> /*
>>  * text
>>  */
>
> Documentation/CodingStyle says net/ and drivers/net/ are special, though
> currently a mix of styles can be found.  Personally, I don't
> particularly care.

OK.

>>> +       nb8800_writel(priv, NB8800_TX_DESC_ADDR, txb->dma_desc);
>>> +       wmb();          /* ensure desc addr is written before starting DMA */
>>
>> Hm… Have I missed corresponding rmb() ? If it's about MMIO, perhaps mmiowb() ?
>
> Possibly.

Standalone wmb() doesn't make sense.

-- 
With Best Regards,
Andy Shevchenko