Re: [PATCH] thunderbolt: Don't display retimers unless nvm was initialized

[Mika Westerberg <mika.westerberg@linux.intel.com>]

Hi Mario,

On Fri, Dec 06, 2024 at 12:33:18PM -0600, Mario Limonciello wrote:
> From: Mario Limonciello <mario.limonciello@amd.com>
> 
> The read will never succeed if nvm wasn't initialized.

Okay but we would need to understand why it was not initialized in the
first place?

I see this is ThinkPad Thunderbolt 4 Dock so probably Intel hardware? You
say you can reproduce this too so can you send me full dmesg with
thunderbolt dynamic debugging enabled? I would like to understand this bit
more deeper before we add any workarounds.

> Reported-by: Richard Hughes <hughsient@gmail.com>
> Closes: https://github.com/fwupd/fwupd/issues/8200
> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
> ---
>  drivers/thunderbolt/retimer.c | 17 ++++++++++++++---
>  1 file changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/thunderbolt/retimer.c b/drivers/thunderbolt/retimer.c
> index 89d2919d0193e..7be435aee7217 100644
> --- a/drivers/thunderbolt/retimer.c
> +++ b/drivers/thunderbolt/retimer.c
> @@ -321,9 +321,7 @@ static ssize_t nvm_version_show(struct device *dev,
>  	if (!mutex_trylock(&rt->tb->lock))
>  		return restart_syscall();
>  
> -	if (!rt->nvm)
> -		ret = -EAGAIN;
> -	else if (rt->no_nvm_upgrade)
> +	if (rt->no_nvm_upgrade)
>  		ret = -EOPNOTSUPP;
>  	else
>  		ret = sysfs_emit(buf, "%x.%x\n", rt->nvm->major, rt->nvm->minor);
> @@ -342,6 +340,18 @@ static ssize_t vendor_show(struct device *dev, struct device_attribute *attr,
>  }
>  static DEVICE_ATTR_RO(vendor);
>  
> +static umode_t retimer_is_visible(struct kobject *kobj,
> +				      struct attribute *attr, int n)
> +{
> +	struct device *dev = kobj_to_dev(kobj);
> +	struct tb_retimer *rt = tb_to_retimer(dev);
> +
> +	if (!rt->nvm)
> +		return 0;
> +	return attr->mode;
> +
> +}
> +
>  static struct attribute *retimer_attrs[] = {
>  	&dev_attr_device.attr,
>  	&dev_attr_nvm_authenticate.attr,
> @@ -351,6 +361,7 @@ static struct attribute *retimer_attrs[] = {
>  };
>  
>  static const struct attribute_group retimer_group = {
> +	.is_visible = retimer_is_visible,
>  	.attrs = retimer_attrs,
>  };
>  
> -- 
> 2.43.0