From: Guenter Roeck linux@roeck-us.net
[ Upstream commit 57b888ca2541785de2fcb90575b378921919b6c0 ]
Commit 413dda8f2c6f ("platform/chrome: cros_ec_chardev: Use cros_ec_cmd_xfer_status helper") inadvertendly changed the userspace ABI. Previously, cros_ec ioctls would only report errors if the EC communication failed, and otherwise return success and the result of the EC communication. An EC command execution failure was reported in the EC response field. The above mentioned commit changed this behavior, and the ioctl itself would fail. This breaks userspace commands trying to analyze the EC command execution error since the actual EC command response is no longer reported to userspace.
Fix the problem by re-introducing the cros_ec_cmd_xfer() helper, and use it to handle ioctl messages.
Fixes: 413dda8f2c6f ("platform/chrome: cros_ec_chardev: Use cros_ec_cmd_xfer_status helper") Cc: Daisuke Nojiri dnojiri@chromium.org Cc: Rob Barnes robbarnes@google.com Cc: Rajat Jain rajatja@google.com Cc: Brian Norris briannorris@chromium.org Cc: Parth Malkan parthmalkan@google.com Reviewed-by: Daisuke Nojiri dnojiri@chromium.org Reviewed-by: Brian Norris briannorris@chromium.org Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Tzung-Bi Shih tzungbi@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/platform/chrome/cros_ec_chardev.c | 2 +- drivers/platform/chrome/cros_ec_proto.c | 50 +++++++++++++++++---- include/linux/platform_data/cros_ec_proto.h | 3 ++ 3 files changed, 45 insertions(+), 10 deletions(-)
diff --git a/drivers/platform/chrome/cros_ec_chardev.c b/drivers/platform/chrome/cros_ec_chardev.c index e0bce869c49a..fd33de546aee 100644 --- a/drivers/platform/chrome/cros_ec_chardev.c +++ b/drivers/platform/chrome/cros_ec_chardev.c @@ -301,7 +301,7 @@ static long cros_ec_chardev_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg) }
s_cmd->command += ec->cmd_offset; - ret = cros_ec_cmd_xfer_status(ec->ec_dev, s_cmd); + ret = cros_ec_cmd_xfer(ec->ec_dev, s_cmd); /* Only copy data to userland if data was received. */ if (ret < 0) goto exit; diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c index a7404d69b2d3..ed2b4807328d 100644 --- a/drivers/platform/chrome/cros_ec_proto.c +++ b/drivers/platform/chrome/cros_ec_proto.c @@ -560,22 +560,28 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev) EXPORT_SYMBOL(cros_ec_query_all);
/** - * cros_ec_cmd_xfer_status() - Send a command to the ChromeOS EC. + * cros_ec_cmd_xfer() - Send a command to the ChromeOS EC. * @ec_dev: EC device. * @msg: Message to write. * - * Call this to send a command to the ChromeOS EC. This should be used instead of calling the EC's - * cmd_xfer() callback directly. It returns success status only if both the command was transmitted - * successfully and the EC replied with success status. + * Call this to send a command to the ChromeOS EC. This should be used instead + * of calling the EC's cmd_xfer() callback directly. This function does not + * convert EC command execution error codes to Linux error codes. Most + * in-kernel users will want to use cros_ec_cmd_xfer_status() instead since + * that function implements the conversion. * * Return: - * >=0 - The number of bytes transferred - * <0 - Linux error code + * >0 - EC command was executed successfully. The return value is the number + * of bytes returned by the EC (excluding the header). + * =0 - EC communication was successful. EC command execution results are + * reported in msg->result. The result will be EC_RES_SUCCESS if the + * command was executed successfully or report an EC command execution + * error. + * <0 - EC communication error. Return value is the Linux error code. */ -int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev, - struct cros_ec_command *msg) +int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev, struct cros_ec_command *msg) { - int ret, mapped; + int ret;
mutex_lock(&ec_dev->lock); if (ec_dev->proto_version == EC_PROTO_VERSION_UNKNOWN) { @@ -616,6 +622,32 @@ int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev, ret = send_command(ec_dev, msg); mutex_unlock(&ec_dev->lock);
+ return ret; +} +EXPORT_SYMBOL(cros_ec_cmd_xfer); + +/** + * cros_ec_cmd_xfer_status() - Send a command to the ChromeOS EC. + * @ec_dev: EC device. + * @msg: Message to write. + * + * Call this to send a command to the ChromeOS EC. This should be used instead of calling the EC's + * cmd_xfer() callback directly. It returns success status only if both the command was transmitted + * successfully and the EC replied with success status. + * + * Return: + * >=0 - The number of bytes transferred. + * <0 - Linux error code + */ +int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev, + struct cros_ec_command *msg) +{ + int ret, mapped; + + ret = cros_ec_cmd_xfer(ec_dev, msg); + if (ret < 0) + return ret; + mapped = cros_ec_map_error(msg->result); if (mapped) { dev_dbg(ec_dev->dev, "Command result (err: %d [%d])\n", diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/platform_data/cros_ec_proto.h index 02599687770c..7f03e02c48cd 100644 --- a/include/linux/platform_data/cros_ec_proto.h +++ b/include/linux/platform_data/cros_ec_proto.h @@ -216,6 +216,9 @@ int cros_ec_prepare_tx(struct cros_ec_device *ec_dev, int cros_ec_check_result(struct cros_ec_device *ec_dev, struct cros_ec_command *msg);
+int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev, + struct cros_ec_command *msg); + int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev, struct cros_ec_command *msg);