Am Donnerstag, 15. Dezember 2016, 08:34:09 CET schrieb Doug Anderson: > Hi, > > On Wed, Dec 14, 2016 at 10:41 PM, Frank Wang <frank.wang@xxxxxxxxxxxxxx> wrote: > > Hi Brain, Doug and Heiko, > > > > I would like to summarize why this story was constructed. > > > > The ehci/ohci-platform suspend process are blocked due to UTMI clock which > > directly output from usb-phy has been disabled, and why the UTMI clock was > > disabled? > > > > UTMI clock and 480m clock all output from the same internal PLL of > > usb-phy, > > and there is only one bit can use to control this PLL on or off, which we > > named "otg_commononn"(GRF, offset 0x0e450/0x0e460 bit4 ) in RK3399 TRM. > > > > When system boot up, ehci/ohci-platform probe function invoke > > phy_power_on(), further invoke rockchip_usb2phy_power_on() to enable 480m > > clock, actually, it sets the otg_commononn bit on, and then usb-phy will > > go > > to (auto)suspend if there is no devices plug-in after 1 minute, the > > rockchip_usb2phy_power_off() will be invoked and the 480m clock may be > > disabled in the (auto)suspend process. As a result, the otg_commononn bit > > may be turned off, and all output clock of usb-phy will be disabled. > > However, ehci/ohci-platform PM suspend operation (read/write controller > > register) are based on the UTMI clock. > > > > So we introduced "clk_usbphy0_480m_src"/"clk_usbphy1_480m_src" as one > > input > > clock for ehci/ohci-platform, in this way, the otg_commononn bit is not > > turned off until ehci/ohci-platform go to PM suspend. > > I still need to digest all of the things that were added to this > thread overnight, but nothing I've seen so far indicates that you need > the post-gated clock. AKA I still think you need to redo your patch > to replace: > > clocks = <&cru HCLK_HOST0>, <&cru HCLK_HOST0_ARB>, > <&cru SCLK_USBPHY0_480M_SRC>; > > with: > > clocks = <&cru HCLK_HOST0>, <&cru HCLK_HOST0_ARB>, > <&u2phy0>; > > Can you please comment on that? Also, with the change, the ehci will keep the clock (and thus the phy) always on. Does the phy-autosuspend even save anything now? In any case, could we make the clock-names entry sound nicer than usbphy0_480m please? bindings/usb/atmel-usb.txt calls its UTMI clock simply "usb_clk", but something like "utmi" should also work. While at it you could also fix up the other clock names to something like "host" and "arbiter" or so?. Heiko -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
