Re: [U-Boot-Users] [PATCH] Add support for Generic PHY in macb
Hi, ----- Messaggio originale -----
Da: Haavard Skinnemoen hskinnemoen@atmel.com A: Michael Trimarchi trimarchimichael@yahoo.it Cc: Michael Schwingen rincewind@discworld.dascon.de; u-boot-users@lists.sourceforge.net Inviato: Venerdì 22 febbraio 2008, 17:08:56 Oggetto: Re: [U-Boot-Users] [PATCH] Add support for Generic PHY in macb
On Fri, 22 Feb 2008 16:02:13 +0000 (GMT) Michael Trimarchi wrote:
In any case, the dm9161a PHY in question does implement MDIO, so it really should work without any modifications.
Maybe we can add the for cycle like in linux to check the phy addr?
Yes, we could do that. But it comes with its own share of problems -- some boards have a too weak pull-up (or none at all) on the MDIO line, so the probing code sometimes thinks it has found a whole bunch of PHYs...
Haavard
But the u-boot user may to choice to use the automatic detection, based on phy_id mask and stop the search on the first one, or somenthing like this.
Michael
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Michael Trimarchi wrote:
Hi, ----- Messaggio originale -----
Da: Haavard Skinnemoen hskinnemoen@atmel.com A: Michael Trimarchi trimarchimichael@yahoo.it Cc: Michael Schwingen rincewind@discworld.dascon.de; u-boot-users@lists.sourceforge.net Inviato: Venerdì 22 febbraio 2008, 17:08:56 Oggetto: Re: [U-Boot-Users] [PATCH] Add support for Generic PHY in macb
On Fri, 22 Feb 2008 16:02:13 +0000 (GMT) Michael Trimarchi wrote:
In any case, the dm9161a PHY in question does implement MDIO, so it really should work without any modifications.
Maybe we can add the for cycle like in linux to check the phy addr?
Yes, we could do that. But it comes with its own share of problems -- some boards have a too weak pull-up (or none at all) on the MDIO line, so the probing code sometimes thinks it has found a whole bunch of PHYs...
Haavard
But the u-boot user may to choice to use the automatic detection, based on phy_id mask and stop the search on the first one, or somenthing like this.
Michael
I don't follow why you'd want to do this. As Andy, Haavard and others have pointed out, you can't probe for PHY addresses because quite often multiple ports will share an MDIO bus, and also it's unreliable at best. Anybody who writes U-boot code needs to know the details of his or her board, and PHY addresses are always fixed in hardware. There may be some reason to make them dynamic, but I can't imagine why.
regards, Ben
participants (2)
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Ben Warren -
Michael Trimarchi