From: Giuseppe CAVALLARO <peppe.cavallaro@st.com>
To: Giulio Benetti <giulio.benetti@micronovasrl.com>
Cc: netdev@vger.kernel.org
Subject: Re: macb phy address bug?
Date: Fri, 14 Nov 2008 09:46:53 +0100 [thread overview]
Message-ID: <491D3AFD.1080509@st.com> (raw)
In-Reply-To: <200811140853.13729.giulio.benetti@micronovasrl.com>
Giulio Benetti wrote:
> PHYID returns 0xffff and not 0xffffffff when not found and in some
> case(at91sam9263) 0x0. Maybe this patch could be useful.
>
>
>
> Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
>
Hi Giulio,
it sounds like a work around for a hardware error.
Is my understanding that, broken hardware is sometimes missing the pull
down resistor on the MDIO line, which results in reads to non-existent
devices returning 0 rather than 0xffff.
Your fix looks good for me, although, I don't know if some vendors
actually use 0 as valid UID.
Moreover, when I met this problem, I decided to move just this hack
within the MAC driver (as soon as the PHY is connected to the driver)
instead of patching the PAL code.
Hoping this could be useful.
Ciao
Peppe
next prev parent reply other threads:[~2008-11-14 8:49 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-14 7:53 macb phy address bug? Giulio Benetti
2008-11-14 8:46 ` Giuseppe CAVALLARO [this message]
-- strict thread matches above, loose matches on Subject: below --
2008-11-16 9:50 David Miller
2008-11-18 8:50 ` Giuseppe CAVALLARO
2008-11-18 11:54 ` Giulio Benetti
2008-11-18 15:35 ` Giuseppe CAVALLARO
2008-11-20 9:04 ` David Miller
2008-11-20 15:59 ` Giuseppe CAVALLARO
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