[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <54FD5ED0.6070208@codethink.co.uk>
Date: Mon, 09 Mar 2015 08:50:24 +0000
From: Ben Dooks <ben.dooks@...ethink.co.uk>
To: Ben Hutchings <ben.hutchings@...ethink.co.uk>,
Geert Uytterhoeven <geert@...ux-m68k.org>
CC: linux-kernel@...ts.codethink.co.uk,
Yoshihiro Kaneko <ykaneko0929@...il.com>,
Sergei Shtylyov <sergei.shtylyov@...entembedded.com>,
Mitsuhiro Kimura <mitsuhiro.kimura.kc@...esas.com>,
netdev@...r.kernel.org,
Yoshihiro Shimoda <yoshihiro.shimoda.uh@...esas.com>,
Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@...esas.com>,
"David S. Miller" <davem@...emloft.net>
Subject: Re: [Linux-kernel] [net-next, 2/5] sh_eth: WARN on access to a register
not implemented in a particular chip
On 05/03/15 13:18, Ben Hutchings wrote:
> On Thu, 2015-03-05 at 10:02 +0100, Geert Uytterhoeven wrote:
>> Replying to a patchwork mbox, as I noticed this is in net-next.
>>
>> On Thu, 26 Feb 2015, Ben Hutchings wrote:
>>> Currently we may silently read/write a register at offset 0. Change
>>> this to WARN and then ignore the write or read-back all-ones.
>>>
>>> Signed-off-by: Ben Hutchings <ben.hutchings@...ethink.co.uk>
>>> Acked-by: Sergei Shtylyov <sergei.shtylyov@...entembedded.com>
>>
>> While this may be a good idea for debugging...
>>
>>> --- a/drivers/net/ethernet/renesas/sh_eth.h
>>> +++ b/drivers/net/ethernet/renesas/sh_eth.h
>>> @@ -543,19 +543,29 @@ static inline void sh_eth_soft_swap(char *src, int len)
>>> #endif
>>> }
>>>
>>> +#define SH_ETH_OFFSET_INVALID ((u16) ~0)
>>> +
>>> static inline void sh_eth_write(struct net_device *ndev, u32 data,
>>> int enum_index)
>>> {
>>> struct sh_eth_private *mdp = netdev_priv(ndev);
does de-referencing this each time make a difference? Looks like
it would have been easier to pass an "struct sh_eth_private" instead
of the "struct net_device *ndev"
>>> + u16 offset = mdp->reg_offset[enum_index];
>>> +
>>> + if (WARN_ON(offset == SH_ETH_OFFSET_INVALID))
>>> + return;
You could cange the mdp->reg_offset to an mdp->reg_pointer and make
any invalid registers a NULL. This would at-least make it fail on an
invalid access.
>> ... adding WARN_ON() to static inline functions increases code size a lot:
>>
>> $ size drivers/net/ethernet/renesas/sh_eth.o{.orig,}
>> text data bss dec hex filename
>> 23352 1136 0 24488 5fa8 drivers/net/ethernet/renesas/sh_eth.o.orig
>> 27225 1136 0 28361 6ec9 drivers/net/ethernet/renesas/sh_eth.o
>> $
>
> Time to un-inline it, maybe?
>
> Ben.
>
>
> _______________________________________________
> linux-kernel mailing list
> linux-kernel@...ts.codethink.co.uk
> https://ducie-dc1.codethink.co.uk/cgi-bin/mailman/listinfo/linux-kernel
>
--
Ben Dooks http://www.codethink.co.uk/
Senior Engineer Codethink - Providing Genius
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists