scottk/OpenCellular
1
0
Fork 0
mirror of https://github.com/Telecominfraproject/OpenCellular.git synced 2026-01-09 17:11:42 +00:00
Code Issues Packages Projects Releases Wiki Activity

Hold I2C lock through entire PD read transaction

Browse Source 
I2C reads from the PD happen in two separate transactions, but no stop
condition is set after the first transcation. Therefore, it is necessary
to lock the I2C bus across both transactions to prevent other tasks
from using the bus in between.

BUG=chrome-os-partner:29839
TEST=Manual on Samus. Boot to recovery screen, plug + unplug power
supply, verify that no I2C error messages are printed to console.
Then repeat 100x.
BRANCH=None.

Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Change-Id: Ie441637f499980a349022e281379ad2cc825b1aa
Reviewed-on: https://chromium-review.googlesource.com/211649
Reviewed-by: Alec Berg <alecaberg@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
This commit is contained in:
Shawn Nematbakhsh
2014-08-08 11:42:18 -07:00
committed by chrome-internal-fetch
parent 0815df9cbf
commit c366c20899
1 changed files with 5 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
common/host_command_master.c
View File

@@ -83,8 +83,8 @@ static int pd_host_command_internal(int command, int version,
&req_buf[0], outsize + sizeof(rq) + 1, &resp_buf[0],
2, I2C_XFER_START);
i2c_set_timeout(I2C_PORT_PD_MCU, 0);
i2c_lock(I2C_PORT_PD_MCU, 0);
if (ret) {
i2c_lock(I2C_PORT_PD_MCU, 0);
CPRINTF("[%T i2c transaction 1 failed: %d]\n", ret);
return -ret;
}
@@ -97,13 +97,16 @@ static int pd_host_command_internal(int command, int version,
ret);
if (resp_len > (insize + sizeof(rs))) {
/* Do a dummy read to generate stop condition */
i2c_xfer(I2C_PORT_PD_MCU, CONFIG_USB_PD_I2C_SLAVE_ADDR,
0, 0, &resp_buf[2], 1, I2C_XFER_STOP);
i2c_lock(I2C_PORT_PD_MCU, 0);
CPRINTF("[%T response size is too large %d > %d]\n",
resp_len, insize + sizeof(rs));
return -EC_RES_RESPONSE_TOO_BIG;
}
/* Receive remaining data */
i2c_lock(I2C_PORT_PD_MCU, 1);
ret = i2c_xfer(I2C_PORT_PD_MCU, CONFIG_USB_PD_I2C_SLAVE_ADDR, 0, 0,
&resp_buf[2], resp_len, I2C_XFER_STOP);
i2c_lock(I2C_PORT_PD_MCU, 0);