Re: [PATCH v3 2/7] clk: rockchip: rk3399: export 480M_SRC clock id for usbphy0/usbphy1
Hi Heiko, On 2016/8/8 17:55, Frank Wang wrote: Hi Heiko, On 2016/8/6 0:05, Heiko Stübner wrote: Hi Frank, Am Freitag, 5. August 2016, 16:34:42 schrieb Frank Wang: On 2016/8/5 3:10, Heiko Stübner wrote: Am Dienstag, 2. August 2016, 15:19:56 schrieb Xing Zheng: Export these source clocks for usbphy. Signed-off-by: Xing Zheng can you please provide a rationale why you need manual control over that intermediate clock? Well, From below graph, you can see that 'clk_usbphyX_480m' is generated from usb2phy, and 'clk_usbphy_480m' which select from clk_usbphyX_480m_src via a gate (G13[12]) provided 480M clock to other modules. xin24m |__ clk_usb2phy0_ref | | | |__ clk_usbphy0_480m | | | |__clk_usbphy0_480m_src || ||__clk_usbphy_480m | |__ ... ... | |__ clk_usb2phy1_ref | |__ clk_usbphy1_480m | |__clk_usbphy1_480m_src The two usbphys seem to use the clk_usb2phyX_ref clocks, generate the 480m clocks, but do not seem to need the clk_usbphyX_480m_src gates. Yeah, they used to be. However, the story went something like this, Some PM suspend process related ehci/ohci controller are base on 480m clocks, unfortunately, usb2-phy suspended earlier than ehci/ohci (usb2-phy will be auto suspended if no devices plug-in), and the clk-480m provided by it was disabled if no module used. As a result, the PM suspend process was blocked when it run into ehci/ohci module. ah, so the ehci controller needs that 480m clock as well? Do you happen to have example patches for the ehci/ohci side already? I'd like to peak at what you mean with "some PM suspend process related" things. Actually, no patches for it, I just make below steps manually :-). 1. set two usb2-phy into suspend mode. 2. disable 480m clock on each usb2-phy (assume only usb2-phy used it). 3. press power button let system into PM suspend. Then, the kernel will be blocked and you can see the following log from console. ... [ 123.763848] calling usb6+ @ 166, parent: xhci-hcd.0.auto [ 123.764503] call usb6+ returned 0 after 163 usecs [ 123.765106] calling usb5+ @ 166, parent: xhci-hcd.0.auto [ 123.765719] call usb5+ returned 0 after 121 usecs [ 123.766294] calling usb4+ @ 166, parent: fe3e.usb [ 123.766917] calling usb3+ @ 55, parent: fe3a.usb May I know have you tried reproducing on your board or not? Depending on what is actually needed, you could also pull the usbphy out of autosuspend in a pm-prepare callback of the phy driver itself ... see http://lxr.free-electrons.com/source/include/linux/pm.h#L86 Like - in the .prepare callback make sure to unsuspend the phy and deactivate the autosuspend - ehci/ohci will poweroff the phy in it s suspend callback (already does that) Hmm, do you remember that we have previously discussed there are some oddities in ehci/ohci driver? phy_power_on() gets called twice at ehci/ohci driver probe time, one is at pdata->power_on(); another is at usb_add_hcd(), then the power_count of phy increases to 2, but phy_power_off() is just invoked one time when ehci/ohci goes to PM suspend, so phy->ops->power_off is never be invoked. In this way, the usb-phy maybe never go to suspend. - suspend -> resume - ehci/ohci will poweron the phy - in the phy's .complete callback you can reactivate the autosuspend timer Because it looks more like you actually need the phy and not the clock alone. So it would be nicer to use mechanisms already in place instead of creating new dependencies. Theoretically, phy_init() will be invoked when ehci/ohci power on, and the sm_work will be reactivated (have already implemented) in phy->ops->init, but unfortunately, the same issue as phy_power_on() mentioned above, it never run there too . Would you like to give some comments on above two oddities please? BR. Frank Hence, we are planing to refer clk_usbphyX_480m_src into each ehci/ohci driver. Maybe you will challenge why not refer clk_usbphy_480m directly? because there are two ehci/ohci connected in the different usb2phy, and only one clk_usbphy_480m clock was selected in clock tree. Nope, no argument from me as I fully understand that each phy provides its own 480m clock :-) . Heiko
Re: [PATCH v3 2/7] clk: rockchip: rk3399: export 480M_SRC clock id for usbphy0/usbphy1
Hi Heiko, On 2016/8/6 0:05, Heiko Stübner wrote: Hi Frank, Am Freitag, 5. August 2016, 16:34:42 schrieb Frank Wang: On 2016/8/5 3:10, Heiko Stübner wrote: Am Dienstag, 2. August 2016, 15:19:56 schrieb Xing Zheng: Export these source clocks for usbphy. Signed-off-by: Xing Zheng can you please provide a rationale why you need manual control over that intermediate clock? Well, From below graph, you can see that 'clk_usbphyX_480m' is generated from usb2phy, and 'clk_usbphy_480m' which select from clk_usbphyX_480m_src via a gate (G13[12]) provided 480M clock to other modules. xin24m |__ clk_usb2phy0_ref | | | |__ clk_usbphy0_480m | | | |__clk_usbphy0_480m_src || ||__clk_usbphy_480m | |__ ... ... | |__ clk_usb2phy1_ref | |__ clk_usbphy1_480m | |__clk_usbphy1_480m_src The two usbphys seem to use the clk_usb2phyX_ref clocks, generate the 480m clocks, but do not seem to need the clk_usbphyX_480m_src gates. Yeah, they used to be. However, the story went something like this, Some PM suspend process related ehci/ohci controller are base on 480m clocks, unfortunately, usb2-phy suspended earlier than ehci/ohci (usb2-phy will be auto suspended if no devices plug-in), and the clk-480m provided by it was disabled if no module used. As a result, the PM suspend process was blocked when it run into ehci/ohci module. ah, so the ehci controller needs that 480m clock as well? Do you happen to have example patches for the ehci/ohci side already? I'd like to peak at what you mean with "some PM suspend process related" things. Actually, no patches for it, I just make below steps manually :-). 1. set two usb2-phy into suspend mode. 2. disable 480m clock on each usb2-phy (assume only usb2-phy used it). 3. press power button let system into PM suspend. Then, the kernel will be blocked and you can see the following log from console. ... [ 123.763848] calling usb6+ @ 166, parent: xhci-hcd.0.auto [ 123.764503] call usb6+ returned 0 after 163 usecs [ 123.765106] calling usb5+ @ 166, parent: xhci-hcd.0.auto [ 123.765719] call usb5+ returned 0 after 121 usecs [ 123.766294] calling usb4+ @ 166, parent: fe3e.usb [ 123.766917] calling usb3+ @ 55, parent: fe3a.usb Depending on what is actually needed, you could also pull the usbphy out of autosuspend in a pm-prepare callback of the phy driver itself ... see http://lxr.free-electrons.com/source/include/linux/pm.h#L86 Like - in the .prepare callback make sure to unsuspend the phy and deactivate the autosuspend - ehci/ohci will poweroff the phy in it s suspend callback (already does that) Hmm, do you remember that we have previously discussed there are some oddities in ehci/ohci driver? phy_power_on() gets called twice at ehci/ohci driver probe time, one is at pdata->power_on(); another is at usb_add_hcd(), then the power_count of phy increases to 2, but phy_power_off() is just invoked one time when ehci/ohci goes to PM suspend, so phy->ops->power_off is never be invoked. In this way, the usb-phy maybe never go to suspend. - suspend -> resume - ehci/ohci will poweron the phy - in the phy's .complete callback you can reactivate the autosuspend timer Because it looks more like you actually need the phy and not the clock alone. So it would be nicer to use mechanisms already in place instead of creating new dependencies. Theoretically, phy_init() will be invoked when ehci/ohci power on, and the sm_work will be reactivated (have already implemented) in phy->ops->init, but unfortunately, the same issue as phy_power_on() mentioned above, it never run there too . Hence, we are planing to refer clk_usbphyX_480m_src into each ehci/ohci driver. Maybe you will challenge why not refer clk_usbphy_480m directly? because there are two ehci/ohci connected in the different usb2phy, and only one clk_usbphy_480m clock was selected in clock tree. Nope, no argument from me as I fully understand that each phy provides its own 480m clock :-) . Heiko
Re: [PATCH v3 2/7] clk: rockchip: rk3399: export 480M_SRC clock id for usbphy0/usbphy1
Hi Frank, Am Freitag, 5. August 2016, 16:34:42 schrieb Frank Wang: > On 2016/8/5 3:10, Heiko Stübner wrote: > > Am Dienstag, 2. August 2016, 15:19:56 schrieb Xing Zheng: > >> Export these source clocks for usbphy. > >> > >> Signed-off-by: Xing Zheng > > > > can you please provide a rationale why you need manual control over that > > intermediate clock? > > Well, From below graph, you can see that 'clk_usbphyX_480m' is generated > from usb2phy, and 'clk_usbphy_480m' which select from > clk_usbphyX_480m_src via a gate (G13[12]) provided 480M clock to other > modules. > >xin24m > >|__ clk_usb2phy0_ref >| >| |__ clk_usbphy0_480m >| | >| |__clk_usbphy0_480m_src >| | >| |__clk_usbphy_480m >| | >| |__ ... ... >| >|__ clk_usb2phy1_ref >| > |__ clk_usbphy1_480m > | > |__clk_usbphy1_480m_src > > > > The two usbphys seem to use the clk_usb2phyX_ref clocks, generate the > > 480m > > clocks, but do not seem to need the clk_usbphyX_480m_src gates. > > Yeah, they used to be. However, the story went something like this, > > Some PM suspend process related ehci/ohci controller are base on 480m > clocks, unfortunately, usb2-phy suspended earlier than ehci/ohci > (usb2-phy will be auto suspended if no devices plug-in), and the > clk-480m provided by it was disabled if no module used. As a result, the > PM suspend process was blocked when it run into ehci/ohci module. ah, so the ehci controller needs that 480m clock as well? Do you happen to have example patches for the ehci/ohci side already? I'd like to peak at what you mean with "some PM suspend process related" things. Depending on what is actually needed, you could also pull the usbphy out of autosuspend in a pm-prepare callback of the phy driver itself ... see http://lxr.free-electrons.com/source/include/linux/pm.h#L86 Like - in the .prepare callback make sure to unsuspend the phy and deactivate the autosuspend - ehci/ohci will poweroff the phy in it s suspend callback (already does that) - suspend -> resume - ehci/ohci will poweron the phy - in the phy's .complete callback you can reactivate the autosuspend timer Because it looks more like you actually need the phy and not the clock alone. So it would be nicer to use mechanisms already in place instead of creating new dependencies. > Hence, we are planing to refer clk_usbphyX_480m_src into each ehci/ohci > driver. Maybe you will challenge why not refer clk_usbphy_480m directly? > because there are two ehci/ohci connected in the different usb2phy, and > only one clk_usbphy_480m clock was selected in clock tree. Nope, no argument from me as I fully understand that each phy provides its own 480m clock :-) . Heiko
Re: [PATCH v3 2/7] clk: rockchip: rk3399: export 480M_SRC clock id for usbphy0/usbphy1
Hi Heiko, On 2016/8/5 3:10, Heiko Stübner wrote: Hi Xing, Am Dienstag, 2. August 2016, 15:19:56 schrieb Xing Zheng: Export these source clocks for usbphy. Signed-off-by: Xing Zheng can you please provide a rationale why you need manual control over that intermediate clock? Well, From below graph, you can see that 'clk_usbphyX_480m' is generated from usb2phy, and 'clk_usbphy_480m' which select from clk_usbphyX_480m_src via a gate (G13[12]) provided 480M clock to other modules. xin24m |__ clk_usb2phy0_ref | |__ clk_usbphy0_480m | |__clk_usbphy0_480m_src | |__clk_usbphy_480m | |__ ... ... |__ clk_usb2phy1_ref |__ clk_usbphy1_480m |__clk_usbphy1_480m_src The two usbphys seem to use the clk_usb2phyX_ref clocks, generate the 480m clocks, but do not seem to need the clk_usbphyX_480m_src gates. Yeah, they used to be. However, the story went something like this, Some PM suspend process related ehci/ohci controller are base on 480m clocks, unfortunately, usb2-phy suspended earlier than ehci/ohci (usb2-phy will be auto suspended if no devices plug-in), and the clk-480m provided by it was disabled if no module used. As a result, the PM suspend process was blocked when it run into ehci/ohci module. Hence, we are planing to refer clk_usbphyX_480m_src into each ehci/ohci driver. Maybe you will challenge why not refer clk_usbphy_480m directly? because there are two ehci/ohci connected in the different usb2phy, and only one clk_usbphy_480m clock was selected in clock tree. BR. Frank The clk_usbphyX_480m_src clocks on the other hand only lead to the clk_usbphy_480m mux, so I'd like some explanation on what you want to achieve here :-) Thanks Heiko
Re: [PATCH v3 2/7] clk: rockchip: rk3399: export 480M_SRC clock id for usbphy0/usbphy1
Hi Xing, Am Dienstag, 2. August 2016, 15:19:56 schrieb Xing Zheng: > Export these source clocks for usbphy. > > Signed-off-by: Xing Zheng can you please provide a rationale why you need manual control over that intermediate clock? The two usbphys seem to use the clk_usb2phyX_ref clocks, generate the 480m clocks, but do not seem to need the clk_usbphyX_480m_src gates. The clk_usbphyX_480m_src clocks on the other hand only lead to the clk_usbphy_480m mux, so I'd like some explanation on what you want to achieve here :-) Thanks Heiko
