Re: [PATCH v3] phy: Add new Exynos5 USB 3.0 PHY driver

From: Tomasz Figa
Date: Fri Feb 14 2014 - 10:47:45 EST


Hi Vivek,

On 14.02.2014 14:53, Vivek Gautam wrote:
Changes from v2:
1) Added support for multiple PHYs (UTMI+ and PIPE3) and
related changes in the driver structuring.


I'm a bit skeptical about this separation. Can the PHY operate with just the
UTMI+ or PIPE3 part enabled alone without the other? Can any PHY consumer
operate this way?

Yes :-)
As also pointed by Kishon the PHY consumer (which is DWC3 in case of
Exynos5 SoC series)
should theoretically be able use either UTMI+ phy for High speed
operations or both (UTMI+ and PIPE3)
for Super Speed operations.

OK, that's fine then. This is the explanation I needed, thanks.


I believe the right thing to do here is to do all the initialization in
.power_on() and let the driver simply call phy_power_on() when it needs the
PHY and phy_power_off() otherwise.

If this is what we should be doing then what will be the purpose of
two separate APIs :
phy_power_on() and phy_init().
Am i missing while understanding the things.


I don't understand this separation as well. Operations that should be done together shouldn't be separated. Is there any case when you can call one of phy_power_on() and phy_init() without calling another one right before/after it?

Best regards,
Tomasz
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