From: Andrew Bresticker <abrestic@xxxxxxxxxxxx> When an EC command returns EC_RES_IN_PROGRESS, we need to query the state of the EC until it indicates that it is no longer busy. Do this in cros_ec_cmd_xfer() under the EC's mutex so that other commands (e.g. keyboard, I2C passtru) aren't issued to the EC while it is working on the in-progress command. The delay in milliseconds and the number of retries are the values that were used by the flashrom tool when retrying commands. Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx> Reviewed-by: Simon Glass <sjg@xxxxxxxxxxxx> Signed-off-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx> --- Changes since v2: - Explain in the commit message from where the delay and retry values come from. Commented by Andrew Bresticker. - Move the needed definitions inside the if block. Suggested by Lee Jones. - Only check if result is EC_RES_IN_PROGRESS instead of checking also if ret is -EAGAIN since the former implies the later. Suggested by Lee Jones. - Use usleep_range() instead of msleep() since doesn't handle values between 1~20. Suggested by Lee Jones. Changes since v1: - The *xfer() calls don't modify the passed cros_ec_command so there is no need to populate it inside the for loop. Suggested by Lee Jones. drivers/mfd/cros_ec.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c index c53804a..af2fadf 100644 --- a/drivers/mfd/cros_ec.c +++ b/drivers/mfd/cros_ec.c @@ -23,6 +23,10 @@ #include <linux/mfd/core.h> #include <linux/mfd/cros_ec.h> #include <linux/mfd/cros_ec_commands.h> +#include <linux/delay.h> + +#define EC_COMMAND_RETRIES 50 +#define EC_RETRY_DELAY_MS 10 int cros_ec_prepare_tx(struct cros_ec_device *ec_dev, struct cros_ec_command *msg) @@ -69,6 +73,36 @@ int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev, mutex_lock(&ec_dev->lock); ret = ec_dev->cmd_xfer(ec_dev, msg); + if (msg->result == EC_RES_IN_PROGRESS) { + int i; + struct cros_ec_command status_msg; + struct ec_response_get_comms_status status; + + status_msg.version = 0; + status_msg.command = EC_CMD_GET_COMMS_STATUS; + status_msg.outdata = NULL; + status_msg.outsize = 0; + status_msg.indata = (uint8_t *)&status; + status_msg.insize = sizeof(status); + + /* + * Query the EC's status until it's no longer busy or + * we encounter an error. + */ + for (i = 0; i < EC_COMMAND_RETRIES; i++) { + usleep_range(EC_RETRY_DELAY_MS, EC_RETRY_DELAY_MS + 1); + + ret = ec_dev->cmd_xfer(ec_dev, &status_msg); + if (ret < 0) + break; + + msg->result = status_msg.result; + if (status_msg.result != EC_RES_SUCCESS) + break; + if (!(status.flags & EC_COMMS_STATUS_PROCESSING)) + break; + } + } mutex_unlock(&ec_dev->lock); return ret; -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html