[PATCH 5/7] mfd: cros_ec: wait for completion of commands that return IN_PROGRESS
From: Javier Martinez Canillas <hidden>
Date: 2014-07-28 12:19:25
Also in:
linux-i2c, linux-samsung-soc
Subsystem:
multifunction devices (mfd), the rest · Maintainers:
Lee Jones, Linus Torvalds
From: Andrew Bresticker <redacted> 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. Signed-off-by: Andrew Bresticker <redacted> Reviewed-by: Simon Glass <sjg@chromium.org> --- drivers/mfd/cros_ec.c | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-)
diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index c53804a..634c434 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)
@@ -65,10 +69,39 @@ EXPORT_SYMBOL(cros_ec_check_result); int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev, struct cros_ec_command *msg) { - int ret; + int ret, i; mutex_lock(&ec_dev->lock); ret = ec_dev->cmd_xfer(ec_dev, msg); + if (ret == -EAGAIN && msg->result == EC_RES_IN_PROGRESS) { + /* + * Query the EC's status until it's no longer busy or + * we encounter an error. + */ + for (i = 0; i < EC_COMMAND_RETRIES; i++) { + struct cros_ec_command status_msg; + struct ec_response_get_comms_status status; + + msleep(EC_RETRY_DELAY_MS); + + 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); + + 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;
--
2.0.0.rc2