On 12/9/22 16:39, Xavier Drudis Ferran wrote:
arch/arm/dts/rk3399.dtsi has a nodeusb_host0_ehci: usb@fe380000 { compatible = "generic-ehci"; with clocks: clocks = <&cru HCLK_HOST0>, <&cru HCLK_HOST0_ARB>, <&u2phy0>; The first 2 refer to nodes with class UCLASS_CLK, but &u2phy0 has class UCLASS_PHY. u2phy0: usb2phy@e450 { compatible = "rockchip,rk3399-usb2phy"; Since clk_get_bulk() only looks for devices with UCLASS_CLK, it fails with -ENODEV and then ehci_usb_probe() aborts. The consequence is peripherals connected to a USB 2 port (e.g. in a Rock Pi 4 the white port, nearer the edge) not being detected. They're detected if CONFIG_USB_OHCI_GENERIC is selected in Kconfig, because ohci_usb_probe() does not abort when one clk_get_by_index() fails, but then they work in USB 1 mode,. rk3399.dtsi comes from linux and the u2phy0 was added[1] to the clock list in: commit b5d1c57299734f5b54035ef2e61706b83041f20c Author: William wu <w...@rock-chips.com> Date: Wed Dec 21 18:41:05 2016 +0800 arm64: dts: rockchip: add u2phy clock for ehci and ohci of rk3399 We found that the suspend process was blocked when it run into ehci/ohci module due to clk-480m of usb2-phy was disabled. [...] Suspend concerns don't apply to U-Boot, and the problem with U-Boot failing to probe EHCI doesn't apply to linux, because in linux rockchip_usb2phy_clk480m_register makes u2phy0 a proper clock provider when called by rockchip_usb2phy_probe(). So I can think of a few alternative solutions: 1- Change ehci_usb_probe() to make it more similar to ohci_usb_probe(), and survive failure to get one clock. Looks a little harder, and I don't know whether it could break something if it ignored a clock that was important for something else than suspend. 2- Change rk3399.dtsi effecttively reverting the linux commit b5d1c57299734f5b54035ef2e61706b83041f20c. This dealigns the .dtsi from linux and seems fragile at the next synchronisation. 3- Change the clock list in rk3399-u-boot.dtsi or somewhere else. This survives .dts* sync but may survive "too much" and miss some change from linux that we might want. 4- Enable CONFIG_USB_OHCI_GENERIC and use the ports in USB 1 mode. This would need to be made for all boards using rk3399. In a simple test reading one file from USB storage it gave 769.5 KiB/s instead of 20.5 MiB/s with solution 2. 5- Trying to replicate linux and have usb2phy somehow provide a clk, or have a separate clock device for usb2phy in addition to the phy device. This series is a second attempt to implement option 5 as Marek Vasut requested in December 5th. Options 1 and 3 didn't get through[2,3]. The first patch in the series (identical to v3) just registers usb2phy as a clock driver (device_bind_driver() didn't work but device_bind_driver_to_node() did), without any specific operations, so that ehci-generic.c finds it and is happy. It worked in my tests on a Rock Pi 4 B+ (rk3399). Since Marek Vasut objected to an operationless driver[4], the second patch adds enable and disable operations adapted from linux prepare and unprepare operations (and round_rate(), which doesn't seem very useful anyway since it's a fixed clock). Since there're no users of this clock in u-boot, I can't see any difference in my tests with only the first patch or both, so I can't be sure it really works if it's ever needed, but it's hopefully more complete. Links: [1] https://lkml.kernel.org/lkml/1731551.Q6cHK6n5ZM@phil/T/ [2] https://patchwork.ozlabs.org/project/uboot/patch/20220701185959.GC1700@begut/#2954536 [3] https://patchwork.ozlabs.org/project/uboot/patch/Y44+ayJfUlI08ptM@localhost/#3016099 [4] https://patchwork.ozlabs.org/project/uboot/patch/Y5IWpjYLB4aXMy9o@localhost/#3018135
+CC Philipp, Quentin
