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Date: Mon, 14 May 2012 15:10:01 +0800
From: Jason Wang <jasowang@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH] Revert "rtl8139: do the network/host
 communication only in normal operating mode"
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To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: aliguori@us.ibm.com, qemu-devel@nongnu.org, avi@redhat.com

On 05/14/2012 02:20 PM, Michael S. Tsirkin wrote:
> On Mon, May 14, 2012 at 01:31:22PM +0800, Jason Wang wrote:
>> >  On 05/10/2012 07:05 PM, Michael S. Tsirkin wrote:
>>> >  >On Thu, May 10, 2012 at 05:31:56PM +0800, Jason Wang wrote:
>>>> >  >>On 05/10/2012 04:54 PM, Michael S. Tsirkin wrote:
>>>>> >  >>>On Thu, May 10, 2012 at 04:37:22PM +0800, Jason Wang wrote:
>>>>>> >  >>>>This reverts commit ff71f2e8cacefae99179993204172bc65e4303df. This is because
>>>>>> >  >>>>the linux 8139cp driver would leave the card in "Config Register Write Enable"
>>>>>> >  >>>>mode after the eeprom were read or write ( which is unexpected in the spec
>>>>>> >  >>>>).
>>>>> >  >>>Could you show where this happens please?
>>>> >  >>Hi Michael:
>>>> >  >>
>>>> >  >>According to the spec:
>>>> >  >>"""
>>>> >  >>Normal(0x00): RTL8139C(L)+ network/host communication mode.
>>>> >  >>...
>>>> >  >>Config. Register Write Enable(0x11): Before writing to the CONFIG0,
>>>> >  >>1, 3, 4 registers, and bits 13, 12, 8 of BMCR (offset 62h-63h), the
>>>> >  >>RTL8139C(L)+ must be placed in this mode. This will protect the
>>>> >  >>RTL8139C(L)+ configuration from accidental change.
>>>> >  >>"""
>>>> >  >>So If I am reading it correctly, guest should place the card in
>>>> >  >>"Normal mode" during transmission and reception. But linux driver
>>>> >  >>would reset the mode to 11 after each read or write to the eeprom,
>>>> >  >>see eeprom_cmd_end() in 8139cp.c.
>>> >  >Which version? The one I see upstream just clears chip select ...
>> >  
>> >  It use writeb(), so in the meantime it also set the high two bits of 9346.
> OK, so that's the bug, right?
> And it's later cleared during normal init, but reading
> eeprom will set it?
>

Right, that's exactly what I mean.