Re: [PATCH] cmd: usb: Prevent reset in usb tree/info command

[Marek Vasut <marex@denx.de>]

On 6/19/23 12:26, Xavier Drudis Ferran wrote:
> When DISTRO_DEFAULTS is not set, the default environment has
> bootcmd=bootflow and this will cause a UCLASS_BOOTDEV device to be
> added as sibling of those UCLASS_BLK devices in boot_targets, until
> boot succeeds from some device. If none succeeds, and usb is in
> boot_targets, and an usb storage device is plugged to some usb port at
> boot time, its UCLASS_MASS_STORAGE device will have a UCLASS_BOOTDEV
> device as child, besides a UCLASS_BLK child.
> 
> If once the boot fails the user enters at the U-Boot shell prompt:
> 
> usb info
> 
> or
> 
> usb tree
> 
> The code in cmd/usb.c will eventually recurse into the UCLASS_BOOTDEV
> and pass a null pointer to usb_device (because it has no parent_priv_).
> This causes a reset.
> 
> Fix it (twice) by checking for null parent_priv_ and adding
> UCLASS_BOOTDEV to the list of ignored class ids before the recursive
> call.
> 
> This prevents the current particular problem with UCLASS_BOOTDEV, even
> in case it ever gets some parent_priv_ struct which is not an
> usb_device, despite being the child of a usb_device->dev. And it also
> prevents possible future problems if other children are added to usb
> devices that don't have parent_priv_ because they are not part of the
> usb tree, just abstractions of functionality (like UCLASS_BLK and
> UCLASS_BOOTDEV are now).
> 
> Signed-off-by: Xavier Drudis Ferran <xdrudis@tinet.cat>
> ---
> 
> v2: added UCLASS_BOOTDEV check (discussion of v1 dried up without much
>      evident consensus, so hopefully Simon Glass likes it better now)
>      [ https://patchwork.ozlabs.org/project/uboot/patch/ZH39SVA1vbZR3+Gk@xdrudis.tinet.cat/ ]
> ---
> 
> Apologies to the people in Cc: for resending this. I had a typo in the
> email list address.

git send-email -v2 would help

Also you can add a CC list into the commit message below --- , then git 
send-email will automatically pick the CC list up. To get a list of 
people to CC , use get-maintainer script.