Hi,
On Wed, Oct 23, 2024 at 07:22:30PM -0700, Amit Sunil Dhamne wrote:
> PD3.1 spec ("8.3.3.3.3 PE_SNK_Wait_for_Capabilities State") mandates
> that the policy engine perform a hard reset when SinkWaitCapTimer
> expires. Instead the code explicitly does a GET_SOURCE_CAP when the
> timer expires as part of SNK_WAIT_CAPABILITIES_TIMEOUT. Due to this the
> following compliance test failures are reported by the compliance tester
> (added excerpts from the PD Test Spec):
>
> * COMMON.PROC.PD.2#1:
> The Tester receives a Get_Source_Cap Message from the UUT. This
> message is valid except the following conditions: [COMMON.PROC.PD.2#1]
> a. The check fails if the UUT sends this message before the Tester
> has established an Explicit Contract
> ...
>
> * TEST.PD.PROT.SNK.4:
> ...
> 4. The check fails if the UUT does not send a Hard Reset between
> tTypeCSinkWaitCap min and max. [TEST.PD.PROT.SNK.4#1] The delay is
> between the VBUS present vSafe5V min and the time of the first bit
> of Preamble of the Hard Reset sent by the UUT.
>
> For the purpose of interoperability, restrict the quirk introduced in
> https://lore.kernel.org/all/20240523171806.223727-1-sebastian.reichel@xxxxxxxxxxxxx/
> to only non self-powered devices as battery powered devices will not
> have the issue mentioned in that commit.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 122968f8dda8 ("usb: typec: tcpm: avoid resets for missing source capability messages")
> Reported-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
> Closes: https://lore.kernel.org/all/CAPTae5LAwsVugb0dxuKLHFqncjeZeJ785nkY4Jfd+M-tCjHSnQ@xxxxxxxxxxxxxx/
> Signed-off-by: Amit Sunil Dhamne <amitsd@xxxxxxxxxx>
> Reviewed-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
> ---
I actually had this constrained to the !self_powered use-case
originally (before sending to the ML). Since I didn't see a good
reason for the extra check, I decided to keep the code simple :)
Reviewed-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
-- Sebastian
> drivers/usb/typec/tcpm/tcpm.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index d6f2412381cf..c8f467d24fbb 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -4515,7 +4515,8 @@ static inline enum tcpm_state hard_reset_state(struct tcpm_port *port)
> return ERROR_RECOVERY;
> if (port->pwr_role == TYPEC_SOURCE)
> return SRC_UNATTACHED;
> - if (port->state == SNK_WAIT_CAPABILITIES_TIMEOUT)
> + if (port->state == SNK_WAIT_CAPABILITIES ||
> + port->state == SNK_WAIT_CAPABILITIES_TIMEOUT)
> return SNK_READY;
> return SNK_UNATTACHED;
> }
> @@ -5043,8 +5044,11 @@ static void run_state_machine(struct tcpm_port *port)
> tcpm_set_state(port, SNK_SOFT_RESET,
> PD_T_SINK_WAIT_CAP);
> } else {
> - tcpm_set_state(port, SNK_WAIT_CAPABILITIES_TIMEOUT,
> - PD_T_SINK_WAIT_CAP);
> + if (!port->self_powered)
> + upcoming_state = SNK_WAIT_CAPABILITIES_TIMEOUT;
> + else
> + upcoming_state = hard_reset_state(port);
> + tcpm_set_state(port, upcoming_state, PD_T_SINK_WAIT_CAP);
> }
> break;
> case SNK_WAIT_CAPABILITIES_TIMEOUT:
>
> base-commit: c6d9e43954bfa7415a1e9efdb2806ec1d8a8afc8
> --
> 2.47.0.105.g07ac214952-goog
>
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