Hi Marek,
On Sun, Dec 3, 2023 at 10:37 PM Marek Vasut marex@denx.de wrote:
On 12/3/23 22:42, Shantur Rathore wrote:
Hi Marek,
On Sun, Dec 3, 2023 at 8:42 PM Marek Vasut marex@denx.de wrote:
On 11/24/23 01:37, Shantur Rathore wrote:
Hi Marek,
Hi,
sorry for the late reply.
>> In my case RockPro64, the power to usb ports onboard is controlled by >> a regulator. >> This regulator is enabled as part of init as here >> https://github.com/u-boot/u-boot/blob/master/arch/arm/dts/rk3399-rockpro64.d... >> >> On init, the usb devices connected to the port are powered up, in my >> case AM8180 (a RTL9210 based ) NVMe to USB enclosure with UAS. >> But the usb controller is only enabled at 'usb start' and by this time >> the device is in some state that it doesn't get detected. >> >> One way to make sure the devices connected to the ports are in an >> initialising state is by issuing a port reset before scanning the >> port. > > Why not remove this regulator-always-on and let the PHY driver turn the > VBUS ON only when it is needed ? > > Wouldn't that solve the problem too AND remove unnecessarily enabled > regulator ? > > [...]
Removing the regulator-always-on does make it work but there are few issues
- regulator is used to control power to multiple ports ( USB3.0 and
USB2.0 in RockPro64 ), so this could lead to all ports turning off if a phy resets / turns off power
I vaguely recall seeing some refcounting patch for regulator subsystem, would that help ?
I don't think this would be a problem for u-boot, but linux maybe.
How so ?
Actually, I am wrong. I wasn't sure if there is refcounting for the regulator subsystem in linux. just found it has so this is null and void.
- Even with regulator-always-on and without this reset port patch,
linux was always able to detect the drive on the port, so there is something missing in u-boot. 3. Looking at usb hub code in Linux, I found that for USB3.0 it tries to reset the port before scanning. The comment says
/* Is a USB 3.0 port in the Inactive or Compliance Mode state? * Port warm reset is required to recover */
i. https://github.com/torvalds/linux/blob/master/drivers/usb/core/hub.c#L5736 ii. https://github.com/torvalds/linux/blob/master/drivers/usb/core/hub.c#L2836
I believe this isn't implemented in u-boot and hence explicit reset of a port fixes the issue.
I feel this is separate issue and what needs to be fixed first is the hard-wired VBus control.
I beg to differ on this, couple of reasons for this
- The same drive works fine without being reset on the USB2.0 ports - this
confirms that the issue is related to USB3.0 only.
This is a separate issue from the hard-wired VBus control. I agree the issue does exist, I would simply like to avoid conflating the hard-wired VBus control with device reset.
- Linux is able to detect the same drive on USB3.0 when u-boot fails - this
confirms issue doesn't lie with regulator-always-on
See above
- The links I pasted earlier mentions that in USB3.0 the ports need reset
and this is done before the port is scanned. Adding the similar reset in u-boot fixes all with the same regulator-always-on. AFAIK u-boot doesn't handle this special USB3.0 case and maybe this is why I was finding a few posts around the drive not being detected in the USB3.0 port in u-boot but works in a USB2.0 port.
I am not disputing the need for USB 3.0 device reset, I believe there are two issues here -- one is the hard-wired VBus regulator -- the other is this USB 3.0 reset. They should both be fixed.
Sure, agreed 100%. Do we need to fix both at the same time? Both patches seem to be independent.
Separate patch for the regulator please .
Thanks, I am working on the regulator patch for rk3399-rockpro64-u-boot but there seems to be a bug in the rk3399-rockpro64.dtsi from linux where the typec phy is configure with wrong regulator and if I do the patch as below
--- a/arch/arm/dts/rk3399-rockpro64-u-boot.dtsi +++ b/arch/arm/dts/rk3399-rockpro64-u-boot.dtsi @@ -22,6 +22,23 @@ }; };
+&vcc5v0_host { + /delete-property/ regulator-always-on; +}; + +&vcc5v0_typec { + /delete-property/ regulator-always-on; +}; + +&vcc5v0_usb { + /delete-property/ regulator-always-on; + /delete-property/ regulator-boot-on; +};
The typec port won't work until I correct the issue with
+&u2phy1_host { + phy-supply = <&vcc5v0_typec>; +}; +
What would be acceptable here? 1. Leave regulator for typec as it was 2. disable regulator-always-on and fix phy here.
Kind regards, Shantur