Re: [PATCH v4 2/3] usb: typec: tcpm: Allow slow charging loops to comply to pSnkStby
From: Greg Kroah-Hartman
Date: Wed Apr 14 2021 - 11:10:03 EST
On Wed, Apr 14, 2021 at 07:26:55AM -0700, Badhri Jagan Sridharan wrote:
> When a PD charger advertising Rp-3.0 is connected to a sink port, the
> sink port current limit would 3A, during SNK_DISCOVERY, till power
> negotiation starts. Once the negotiation starts the power limit needs
> to drop down to pSnkStby(500mA @ 5V) and to negotiated current limit
> once the explicit contract is in place. Not all charging loops can ramp
> up to 3A and drop down to 500mA within tSnkStdby which is 15ms. The port
> partner might hard reset if tSnkStdby is not met.
>
> To solve this problem, this patch introduces slow-charger-loop which
> when set makes the port request PD_P_SNK_STDBY_MW upon entering
> SNK_DISCOVERY(instead of 3A or the 1.5A during SNK_DISCOVERY) and the
> actual currrent limit after RX of PD_CTRL_PSRDY for PD link or during
> SNK_READY for non-pd link.
>
> Signed-off-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
> Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> Changes since V3:
> * Added reviewed-by tag from Heikki
No need to add reviewed-by tags, my tools pick that up already.
Patches 1 and 2 now queued up.
thanks,
greg k-h