Re: [PATCH 3/3] PCI: mediatek-gen3: Move reset/assert callbacks in .power_up()

["Jianjun Wang (王建军)" <Jianjun.Wang@mediatek.com>]

On Thu, 2024-11-07 at 10:21 -0600, Bjorn Helgaas wrote:
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> 
> On Thu, Nov 07, 2024 at 05:08:55PM +0100, Lorenzo Bianconi wrote:
> > > On Thu, Nov 07, 2024 at 02:50:55PM +0100, Lorenzo Bianconi wrote:
> > > > In order to make the code more readable, move phy and mac reset
> > > > lines
> > > > assert/de-assert configuration in .power_up callback
> > > > (mtk_pcie_en7581_power_up/mtk_pcie_power_up).
> > 
> > ...
> > > Is there a requirement that the PHY and MAC reset ordering be
> > > different for EN7581 vs other chips?
> > > 
> > > EN7581:
> > > 
> > >   assert PHY reset
> > >   assert MAC reset
> > >   power on PHY
> > >   deassert PHY reset
> > >   deassert MAC reset
> > > 
> > > others:
> > > 
> > >   assert PHY reset
> > >   assert MAC reset
> > >   deassert PHY reset
> > >   power on PHY
> > >   deassert MAC reset
> > > 
> > > Is there one order that would work for both?
> > 
> > EN7581 requires to run phy_init()/phy_power_on() before deassert
> > PHY reset
> > lines.
> 
> And the other chips require the PHY power-on to be *after*
> deasserting
> PHY reset?

For MediaTek's chips, the reset will clear all register values and
reset the hardware state. Therefore, we can only initialize and power-
on the MAC and PHY after deasserting their resets.

Thanks.