projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| 4d6421f7 GKH |
1 | From 976daf9d1199932df80e7b04546d1a1bd4ed5ece Mon Sep 17 00:00:00 2001 |
| 2 | From: Hans de Goede <hdegoede@redhat.com> | |
| 3 | Date: Sat, 16 Mar 2019 16:57:12 +0100 | |
| 4 | Subject: usb: typec: tcpm: Try PD-2.0 if sink does not respond to 3.0 source-caps | |
| 5 | ||
| 6 | From: Hans de Goede <hdegoede@redhat.com> | |
| 7 | ||
| 8 | commit 976daf9d1199932df80e7b04546d1a1bd4ed5ece upstream. | |
| 9 | ||
| 10 | PD 2.0 sinks are supposed to accept src-capabilities with a 3.0 header and | |
| 11 | simply ignore any src PDOs which the sink does not understand such as PPS | |
| 12 | but some 2.0 sinks instead ignore the entire PD_DATA_SOURCE_CAP message, | |
| 13 | causing contract negotiation to fail. | |
| 14 | ||
| 15 | This commit fixes such sinks not working by re-trying the contract | |
| 16 | negotiation with PD-2.0 source-caps messages if we don't have a contract | |
| 17 | after PD_N_HARD_RESET_COUNT hard-reset attempts. | |
| 18 | ||
| 19 | The problem fixed by this commit was noticed with a Type-C to VGA dongle. | |
| 20 | ||
| 21 | Signed-off-by: Hans de Goede <hdegoede@redhat.com> | |
| 22 | Reviewed-by: Guenter Roeck <linux@roeck-us.net> | |
| 23 | Cc: stable <stable@vger.kernel.org> | |
| 24 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
| 25 | ||
| 26 | --- | |
| 27 | drivers/usb/typec/tcpm/tcpm.c | 27 ++++++++++++++++++++++++++- | |
| 28 | 1 file changed, 26 insertions(+), 1 deletion(-) | |
| 29 | ||
| 30 | --- a/drivers/usb/typec/tcpm/tcpm.c | |
| 31 | +++ b/drivers/usb/typec/tcpm/tcpm.c | |
| 32 | @@ -37,6 +37,7 @@ | |
| 33 | S(SRC_ATTACHED), \ | |
| 34 | S(SRC_STARTUP), \ | |
| 35 | S(SRC_SEND_CAPABILITIES), \ | |
| 36 | + S(SRC_SEND_CAPABILITIES_TIMEOUT), \ | |
| 37 | S(SRC_NEGOTIATE_CAPABILITIES), \ | |
| 38 | S(SRC_TRANSITION_SUPPLY), \ | |
| 39 | S(SRC_READY), \ | |
| 40 | @@ -2966,10 +2967,34 @@ static void run_state_machine(struct tcp | |
| 41 | /* port->hard_reset_count = 0; */ | |
| 42 | port->caps_count = 0; | |
| 43 | port->pd_capable = true; | |
| 44 | - tcpm_set_state_cond(port, hard_reset_state(port), | |
| 45 | + tcpm_set_state_cond(port, SRC_SEND_CAPABILITIES_TIMEOUT, | |
| 46 | PD_T_SEND_SOURCE_CAP); | |
| 47 | } | |
| 48 | break; | |
| 49 | + case SRC_SEND_CAPABILITIES_TIMEOUT: | |
| 50 | + /* | |
| 51 | + * Error recovery for a PD_DATA_SOURCE_CAP reply timeout. | |
| 52 | + * | |
| 53 | + * PD 2.0 sinks are supposed to accept src-capabilities with a | |
| 54 | + * 3.0 header and simply ignore any src PDOs which the sink does | |
| 55 | + * not understand such as PPS but some 2.0 sinks instead ignore | |
| 56 | + * the entire PD_DATA_SOURCE_CAP message, causing contract | |
| 57 | + * negotiation to fail. | |
| 58 | + * | |
| 59 | + * After PD_N_HARD_RESET_COUNT hard-reset attempts, we try | |
| 60 | + * sending src-capabilities with a lower PD revision to | |
| 61 | + * make these broken sinks work. | |
| 62 | + */ | |
| 63 | + if (port->hard_reset_count < PD_N_HARD_RESET_COUNT) { | |
| 64 | + tcpm_set_state(port, HARD_RESET_SEND, 0); | |
| 65 | + } else if (port->negotiated_rev > PD_REV20) { | |
| 66 | + port->negotiated_rev--; | |
| 67 | + port->hard_reset_count = 0; | |
| 68 | + tcpm_set_state(port, SRC_SEND_CAPABILITIES, 0); | |
| 69 | + } else { | |
| 70 | + tcpm_set_state(port, hard_reset_state(port), 0); | |
| 71 | + } | |
| 72 | + break; | |
| 73 | case SRC_NEGOTIATE_CAPABILITIES: | |
| 74 | ret = tcpm_pd_check_request(port); | |
| 75 | if (ret < 0) { |