[PATCH v2 2/5] configs: ds414: Enable XHCI_PCI by default

[Stefan Roese]

On 05.03.21 21:03, Phil Sutter wrote:
> With the recent fixes in pci_mvebu and xhci-pci drivers, the two rear
> USB3 ports are finally usable and accessing them no longer hangs the
> system. Moreover, if Linux is booted without a prior call to 'pci enum'
> and 'usb start', the HCD is detected but attached devices are not
> usable:
> 
> | xhci_hcd 0000:02:00.0: xHCI Host Controller
> | xhci_hcd 0000:02:00.0: new USB bus registered, assigned bus number 2
> | xhci_hcd 0000:02:00.0: hcc params 0x040040a5 hci version 0x100 quirks 0x0000000000080490
> | usb usb2: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 5.04
> | usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
> | usb usb2: Product: xHCI Host Controller
> | usb usb2: Manufacturer: Linux 5.4.92-1 xhci-hcd
> | usb usb2: SerialNumber: 0000:02:00.0
> | hub 2-0:1.0: USB hub found
> | ata1: SATA link down (SStatus 0 SControl 300)
> | hub 2-0:1.0: 2 ports detected
> | xhci_hcd 0000:02:00.0: xHCI Host Controller
> | xhci_hcd 0000:02:00.0: new USB bus registered, assigned bus number 3
> | xhci_hcd 0000:02:00.0: Host supports USB 3.0 SuperSpeed
> | usb usb3: We don't know the algorithms for LPM for this host, disabling LPM.
> | usb usb3: New USB device found, idVendor=1d6b, idProduct=0003, bcdDevice= 5.04
> | usb usb3: New USB device strings: Mfr=3, Product=2, SerialNumber=1
> | usb usb3: Product: xHCI Host Controller
> | usb usb3: Manufacturer: Linux 5.4.92-1 xhci-hcd
> | usb usb3: SerialNumber: 0000:02:00.0
> | hub 3-0:1.0: USB hub found
> | hub 3-0:1.0: 2 ports detected
> [...]
> | xhci_hcd 0000:02:00.0: Error while assigning device slot ID
> | xhci_hcd 0000:02:00.0: Max number of devices this xHCI host supports is 64.
> | usb usb2-port2: couldn't allocate usb_device
> 
> To avoid this problem, enumerate PCI (and USB) from PREBOOT.
> 
> Signed-off-by: Phil Sutter <phil at nwl.cc>
> ---
> Changes since v1:
> - Have to enable XHCI_HCD as well to fulfill Kconfig dependency.
> - Explicitly disable XHCI_MARVELL which defaults to enabled.
> - Prefix PREBOOT with 'pci enum'.
> - Update commit message accordingly.

Hmmm, in general is should not be necessary to configure / setup any of
the devices in the bootloader so that it works correctly in Linux. It's
best practice, that Linux does not rely on any bootloader setup. If a
device, like PCI and/or USB does not work in Linux without this U-Boot
setup, then it should be fixed in Linux instead.

Especially calling "usb start" adds a quite big delay to the bootup
time. I would really like to not add such changes. Perhaps you could
check with the maintainer(s) of the Linux PCI driver and/or the USB
PCI controller driver about this issue instead?

Thanks,
Stefan

> ---
>   configs/ds414_defconfig | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/configs/ds414_defconfig b/configs/ds414_defconfig
> index 3e6dcec3edde3..24466d81dffdb 100644
> --- a/configs/ds414_defconfig
> +++ b/configs/ds414_defconfig
> @@ -22,7 +22,7 @@ CONFIG_BOOTDELAY=3
>   CONFIG_USE_BOOTARGS=y
>   CONFIG_BOOTARGS="console=ttyS0,115200"
>   CONFIG_USE_PREBOOT=y
> -CONFIG_PREBOOT="usb start; sf probe"
> +CONFIG_PREBOOT="pci enum; usb start; sf probe"
>   # CONFIG_DISPLAY_BOARDINFO is not set
>   CONFIG_DISPLAY_BOARDINFO_LATE=y
>   CONFIG_SPL_I2C_SUPPORT=y
> @@ -65,5 +65,8 @@ CONFIG_SYS_NS16550=y
>   CONFIG_KIRKWOOD_SPI=y
>   CONFIG_USB=y
>   CONFIG_DM_USB=y
> +CONFIG_USB_XHCI_HCD=y
> +# CONFIG_USB_XHCI_MVEBU is not set
> +CONFIG_USB_XHCI_PCI=y
>   CONFIG_USB_EHCI_HCD=y
>   CONFIG_USB_STORAGE=y
> 


Viele Grüße,
Stefan

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