Re: [PATCH 3/3] mfd: cros_ec: Add support for dumping panic information

From: Guenter Roeck
Date: Tue Aug 23 2016 - 17:19:37 EST


On Mon, Aug 22, 2016 at 9:34 PM, Nicolas Boichat <drinkcat@xxxxxxxxxxxx> wrote:
> This dumps the EC panic information from the previous reboot.
>
> Similar to the information presented by ectool panicinfo, except
> that we do not bother doing any parsing (we should write a small
> offline tool for that).
>
> Signed-off-by: Nicolas Boichat <drinkcat@xxxxxxxxxxxx>

Reviewed-by: Guenter Roeck <groeck@xxxxxxxxxxxx>

> ---
> drivers/platform/chrome/cros_ec_debugfs.c | 54 +++++++++++++++++++++++++++++++
> 1 file changed, 54 insertions(+)
>
> diff --git a/drivers/platform/chrome/cros_ec_debugfs.c b/drivers/platform/chrome/cros_ec_debugfs.c
> index 225f936..f4b6a29 100644
> --- a/drivers/platform/chrome/cros_ec_debugfs.c
> +++ b/drivers/platform/chrome/cros_ec_debugfs.c
> @@ -47,15 +47,19 @@
> * @log_mutex: mutex to protect circular buffer
> * @log_wq: waitqueue for log readers
> * @log_poll_work: recurring task to poll EC for new console log data
> + * @panicinfo_blob: panicinfo debugfs blob
> */
> struct cros_ec_debugfs {
> struct cros_ec_dev *ec;
> struct dentry *dir;
> + /* EC log */
> struct circ_buf log_buffer;
> struct cros_ec_command *read_msg;
> struct mutex log_mutex;
> wait_queue_head_t log_wq;
> struct delayed_work log_poll_work;
> + /* EC panicinfo */
> + struct debugfs_blob_wrapper panicinfo_blob;
> };
>
> /*
> @@ -308,6 +312,52 @@ static void cros_ec_cleanup_console_log(struct cros_ec_debugfs *debug_info)
> }
> }
>
> +static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info)
> +{
> + struct cros_ec_device *ec_dev = debug_info->ec->ec_dev;
> + int ret;
> + struct cros_ec_command *msg;
> + int insize;
> +
> + insize = ec_dev->max_response;
> +
> + msg = devm_kzalloc(debug_info->ec->dev,
> + sizeof(*msg) + insize, GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
> +
> + msg->command = EC_CMD_GET_PANIC_INFO;
> + msg->insize = insize;
> +
> + ret = cros_ec_cmd_xfer(ec_dev, msg);
> + if (ret < 0) {
> + dev_warn(debug_info->ec->dev, "Cannot read panicinfo.\n");
> + ret = 0;
> + goto free;
> + }
> +
> + /* No panic data */
> + if (ret == 0)
> + goto free;
> +
> + debug_info->panicinfo_blob.data = msg->data;
> + debug_info->panicinfo_blob.size = ret;
> +
> + if (!debugfs_create_blob("panicinfo",
> + S_IFREG | S_IRUGO,
> + debug_info->dir,
> + &debug_info->panicinfo_blob)) {
> + ret = -ENOMEM;
> + goto free;
> + }
> +
> + return 0;
> +
> +free:
> + devm_kfree(debug_info->ec->dev, msg);
> + return ret;
> +}
> +
> int cros_ec_debugfs_init(struct cros_ec_dev *ec)
> {
> struct cros_ec_platform *ec_platform = dev_get_platdata(ec->dev);
> @@ -324,6 +374,10 @@ int cros_ec_debugfs_init(struct cros_ec_dev *ec)
> if (!debug_info->dir)
> return -ENOMEM;
>
> + ret = cros_ec_create_panicinfo(debug_info);
> + if (ret)
> + goto remove_debugfs;
> +
> ret = cros_ec_create_console_log(debug_info);
> if (ret)
> goto remove_debugfs;
> --
> 2.8.0.rc3.226.g39d4020
>