On 05/12/12 02:14, the mail apparently from Sarah Sharp included:
On Tue, Dec 04, 2012 at 11:40:05AM +0800, Andy Green wrote:
On 04/12/12 01:09, the mail apparently from Alan Stern included:
On Mon, 3 Dec 2012, Andy Green wrote:
Unless someone NAKs it for sure already (if you're already sure you're
going to, please do so to avoid wasting time), I'll issue a try#2 of my
code later which demonstrates what I mean. At least I guess it's useful
for comparative purposes.
Before you go writing a whole lot more code, we should discuss the
basics a bit more clearly. There are several unsettled issues here:
1. Should the LAN95xx stuff be associated with the ehci-omap.0's
driver or with the hub port? The port would be more flexible,
offering the ability to turn the power off and on while the
system is running without affecting anything else. But the
port code is currently in flux, which could cause this new
addition to be delayed.
I think associating ULPI PHY reset and SMSC power and reset with the
hub port power state is good. Then, you could have the driver in a
device with multiple onboard USB devices, and individually control
whether they're eating power or not. In the asset case, you'd
associate mux assets with ehci-omap.0.
Yesterday I studied the hub port code and have a couple of patches,
one normalizes the hub port device to have a stub driver.
The other then puts hub port power state signalling into runtime_pm
handlers in the hub port device. Until now, actually there's no
code in hub.c to switch off a port.
Did you take a look at the most recent patches from Tianyu to add
support to power off a port if a device is suspended?
Start of the series:
http://marc.info/?l=linux-usb&m=135314427413307&w=2
Patch that adds power off on device suspend:
http://marc.info/?l=linux-usb&m=135314431913321&w=2
Tianyu also added some code to the xHCI host controller driver to call
into the ACPI methods to power off a port when the USB hub driver clears
the port power feature.
No I didn't know about it, I will study these along with pm_domain stuff
thanks.
-Andy
--
Andy Green | TI Landing Team Leader
Linaro.org │ Open source software for ARM SoCs | Follow Linaro
http://facebook.com/pages/Linaro/155974581091106 -
http://twitter.com/#!/linaroorg - http://linaro.org/linaro-blog
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
