Re: [PATCH v3] platform/chrome: cros_ec_typec: Stop altmode work during partner removal

[Andrei Kuchynski]

On Sun, Oct 18, 2026 at 4:34 AM Myeonghun Pak <mhun512@xxxxxxxxx> wrote:
>
> DisplayPort and Thunderbolt port altmodes queue work to deliver VDM
> responses to partner drivers. Partner altmode unregistration does not
> drain this work, so it can run while the partner driver is being removed
> and access released driver data.
>
> Look up the corresponding port altmode with typec_altmode_get_partner()
> and disable its work before unregistering the partner altmode. Keep the
> work disabled while the partner driver is removed, then clear pending
> response and DP status state before re-enabling it for a new connection.
> Use the same cleanup when list-node allocation fails after registering
> an altmode.
>
> This issue was identified as part of our ongoing research while
> reviewing kernel code.
>
> Fixes: dbb3fc0ffa95 ("platform/chrome: cros_ec_typec: Displayport support")
> Cc: stable@xxxxxxxxxxxxxxx
> Assisted-by: LLM
> Co-developed-by: Ijae Kim <ae878000@xxxxxxxxx>
> Signed-off-by: Ijae Kim <ae878000@xxxxxxxxx>
> Signed-off-by: Myeonghun Pak <mhun512@xxxxxxxxx>

Tested-by: Andrei Kuchynski <akuchynski@xxxxxxxxxxxx>
---
> +void cros_typec_enable_altmode(const struct typec_altmode *alt, bool enable)
> +{
> +       struct cros_typec_altmode_data *adata = dev_get_drvdata(&alt->dev);
> +       struct cros_typec_dp_data *dp_data;
> +
> +       /* An altmode without its optional implementation has no work. */
> +       if (!adata)
> +               return;
> +
> +       if (!enable) {
> +               disable_work_sync(&adata->work);
> +               return;
> +       }
> +
> +       mutex_lock(&adata->lock);

That won't be necessary, as there is no activity at the moment.

Thanks,
Andrei