diff options
| author | Aaron Durbin <adurbin@chromium.org> | 2014-08-12 22:52:00 -0500 |
|---|---|---|
| committer | chrome-internal-fetch <chrome-internal-fetch@google.com> | 2014-08-14 20:28:48 +0000 |
| commit | 776658d8a23911d3123742008fd4ba1e9b33665e (patch) | |
| tree | 2aaf7b81c07b033202fd3c0d498f6b6983f5e368 | |
| parent | 80f5d9e10a04f3fc4234fce304ba742aee16c1f9 (diff) | |
| download | chrome-ec-776658d8a23911d3123742008fd4ba1e9b33665e.tar.gz | |
stfm32f0: always send bytes over i2c for EC command responses
Certain i2c host drivers don't allow one to snoop the byte
stream to abort a transaction. Allow those devices to make
forward progress by sending out the '0xec' byte for any
requests coming through after an EC host command error.
BUG=chrome-os-partner:30784
BRANCH=None
TEST=Ran on ryu. Allowed passthru probing which normally hung
the system because of there not being a passthrue device
on ryu -- error returned. Instead the command returns
successfully by returning 0xec for the unfilled bytes.
Change-Id: Ibcab5ade1f727f3852995437105eb9fa693caadf
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/212165
Reviewed-by: Alec Berg <alecaberg@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
| -rw-r--r-- | chip/stm32/i2c-stm32f0.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/chip/stm32/i2c-stm32f0.c b/chip/stm32/i2c-stm32f0.c index 1a289393d4..11dd4c7ba4 100644 --- a/chip/stm32/i2c-stm32f0.c +++ b/chip/stm32/i2c-stm32f0.c @@ -153,6 +153,14 @@ static void i2c_send_response_packet(struct host_packet *pkt) /* I2C is slow, so let other things run while we wait */ usleep(50); } + + /* + * If an error occurred. Set the transmitter not full so as to keep + * sending '0xec' in the event loop. That way the master doesn't have + * to snoop the response stream. + */ + if (pkt->driver_result != EC_RES_SUCCESS) + STM32_I2C_CR1(host_i2c_resp_port) |= STM32_I2C_CR1_TXIE; } /* Process the command in the i2c host buffer */ |