diff options
| author | Vic Yang <victoryang@chromium.org> | 2014-08-06 17:52:30 -0700 |
|---|---|---|
| committer | chrome-internal-fetch <chrome-internal-fetch@google.com> | 2014-08-11 09:05:23 +0000 |
| commit | 5ab558117d1953490140b20dea98fac30bbfff06 (patch) | |
| tree | 4010b5bd5fae95e4ea2015197a8e749fba2a76f3 | |
| parent | 0d4529c8481a8f4e00ea351a63b0d11d0bb9efe2 (diff) | |
| download | chrome-ec-5ab558117d1953490140b20dea98fac30bbfff06.tar.gz | |
pd: use interrupt on Rx retry
After sending a message, we wait for up to 2.7 ms for reply. If we don't
get one, we retry for up to twice. Therefore, a undelivered message
could take up to >8ms. To prevent starving other tasks, let's yield to
other tasks on retries and rely on interrupt to wake us.
BUG=chrome-os-partner:28341
TEST=Plug in zinger on port 0 and C-to-A dongle on port 1. Check that
port 0 drops connection less frequently.
BRANCH=None
Change-Id: If85a70fd1140fef69d79243b198703ce601f8030
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/211281
Reviewed-by: Alec Berg <alecaberg@chromium.org>
| -rw-r--r-- | chip/stm32/usb_pd_phy.c | 4 | ||||
| -rw-r--r-- | common/usb_pd_protocol.c | 16 | ||||
| -rw-r--r-- | include/usb_pd.h | 3 |
3 files changed, 19 insertions, 4 deletions
diff --git a/chip/stm32/usb_pd_phy.c b/chip/stm32/usb_pd_phy.c index bbe923b024..a19bcc7969 100644 --- a/chip/stm32/usb_pd_phy.c +++ b/chip/stm32/usb_pd_phy.c @@ -531,8 +531,8 @@ void pd_hw_init(int port) /* Auto-reload value : 16-bit free running counter */ phy->tim_rx->arr = 0xFFFF; - /* Timeout for message receive : 2.7ms */ - phy->tim_rx->ccr[2] = 2400000 * 27 / 10000; + /* Timeout for message receive */ + phy->tim_rx->ccr[2] = (2400000 / 1000) * USB_PD_RX_TMOUT_US / 1000; /* Timer ICx input configuration */ if (TIM_CCR_IDX(port) == 1) phy->tim_rx->ccmr1 |= TIM_CCR_CS << 0; diff --git a/common/usb_pd_protocol.c b/common/usb_pd_protocol.c index 80aeb7b860..371e03ead5 100644 --- a/common/usb_pd_protocol.c +++ b/common/usb_pd_protocol.c @@ -334,8 +334,20 @@ static int send_validate_message(int port, uint16_t header, /* Transmit the packet */ pd_start_tx(port, pd[port].polarity, bit_len); pd_tx_done(port, pd[port].polarity); - /* starting waiting for GoodCrc */ - pd_rx_start(port); + /* + * If we failed the first try, enable interrupt and yield + * to other tasks, so that we don't starve them. + */ + if (r) { + pd_rx_enable_monitoring(port); + /* Message receive timeout is 2.7ms */ + if (task_wait_event(USB_PD_RX_TMOUT_US) == + TASK_EVENT_TIMER) + continue; + } else { + /* starting waiting for GoodCrc */ + pd_rx_start(port); + } /* read the incoming packet if any */ head = analyze_rx(port, payload); pd_rx_complete(port); diff --git a/include/usb_pd.h b/include/usb_pd.h index e472e5bcf5..38f58f5888 100644 --- a/include/usb_pd.h +++ b/include/usb_pd.h @@ -133,6 +133,9 @@ enum pd_errors { /* USB Vendor ID assigned to Google Inc. */ #define USB_VID_GOOGLE 0x18d1 +/* Timeout for message receive in microseconds */ +#define USB_PD_RX_TMOUT_US 2700 + /* --- Protocol layer functions --- */ #ifdef CONFIG_USB_PD_DUAL_ROLE |