On Tue, Jan 10, 2012 at 4:54 PM, Adrian Chadd <adr...@freebsd.org> wrote:
> On 10 January 2012 13:25, Daniel Smith <viscous.liq...@gmail.com> wrote:
>> We actually had the exact same problem with a board we were
>> prototyping on. Working with the manufacturer it turned out to be a
>> "feature" of the AMI BIOS they were using on the card (sorry I don't
>> have the version right off hand). What happens is that the AMI BIOS
>> does a Root Bridge reset on all the PCI-e buses upon power on. This
>> reset can interfere with the initialization of certain types of cards
>> that have serial eeprom that are based off an R-C time constant
>> circuit at Power-On. Luckily for us the manufacturer was willing to
>> patch the BIOS and resolved our issue. Perhaps you can contact
>> Portwell with this info and see if they are willing to help.
> Hi,
> So how exactly did it interfere with it?
> Adrian

IANAEE, but as I understand the explanation it was that a typically
Root Bridge reset is not supposed to occur until later in the
initialization. In this case, the version of AMI that was on this
board did a reset at power-on and then the required one later. This
first reset interferes with serial eeprom loader and causes it to stop
in the middle of initialization. So when the second reset comes along
the cards do not properly enumerate on the bus properly and you end up
with cards in the reported state. The fix the manufacturer did was to
remove the first Root Bridge reset from the BIOS code, after that our
cards would initialize and enumerate onto the bus properly.

ath9k-devel mailing list

Reply via email to