Re: [PATCH V3 2/4] mmc: debugfs: Add debug fs entry for mmc driver

From: Adrian Hunter
Date: Fri Jan 21 2022 - 02:10:26 EST


On 20/01/2022 19:26, Shaik Sajida Bhanu wrote:
> Add debug fs entry to query eMMC and SD card errors statistics
>
> Signed-off-by: Shaik Sajida Bhanu <quic_c_sbhanu@xxxxxxxxxxx>
> Signed-off-by: Liangliang Lu <luliang@xxxxxxxxxxxxxx>
> Signed-off-by: Sayali Lokhande <sayalil@xxxxxxxxxxxxxx>
> Signed-off-by: Bao D. Nguyen <nguyenb@xxxxxxxxxxxxxx>
> ---
> drivers/mmc/core/debugfs.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 81 insertions(+)
>
> diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c
> index 3fdbc80..f4cb594 100644
> --- a/drivers/mmc/core/debugfs.c
> +++ b/drivers/mmc/core/debugfs.c
> @@ -223,6 +223,82 @@ static int mmc_clock_opt_set(void *data, u64 val)
> DEFINE_DEBUGFS_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
> "%llu\n");
>
> +static int mmc_err_state_get(void *data, u64 *val)
> +{
> + struct mmc_host *host = data;
> +
> + if (!host)
> + return -EINVAL;
> +
> + *val = host->err_state ? 1 : 0;
> +
> + return 0;
> +}
> +
> +DEFINE_SIMPLE_ATTRIBUTE(mmc_err_state, mmc_err_state_get, NULL, "%llu\n");
> +
> +static int mmc_err_stats_show(struct seq_file *file, void *data)
> +{
> + struct mmc_host *host = (struct mmc_host *)file->private;
> + const char *desc[MMC_ERR_MAX] = {
> + [MMC_ERR_CMD_TIMEOUT] = "Command Timeout Occurred",
> + [MMC_ERR_CMD_CRC] = "Command CRC Errors Occurred",
> + [MMC_ERR_DAT_TIMEOUT] = "Data Timeout Occurred",
> + [MMC_ERR_DAT_CRC] = "Data CRC Errors Occurred",
> + [MMC_ERR_AUTO_CMD] = "Auto-Cmd Error Occurred",
> + [MMC_ERR_ADMA] = "ADMA Error Occurred",
> + [MMC_ERR_TUNING] = "Tuning Error Occurred",
> + [MMC_ERR_CMDQ_RED] = "CMDQ RED Errors",
> + [MMC_ERR_CMDQ_GCE] = "CMDQ GCE Errors",
> + [MMC_ERR_CMDQ_ICCE] = "CMDQ ICCE Errors",
> + [MMC_ERR_REQ_TIMEOUT] = "Request Timedout",
> + [MMC_ERR_CMDQ_REQ_TIMEOUT] = "CMDQ Request Timedout",
> + [MMC_ERR_ICE_CFG] = "ICE Config Errors",
> + };
> + int i;
> +
> + if (!host)
> + return -EINVAL;
> +
> + if (!host->err_stats_enabled) {
> + seq_printf(file, "Not supported by driver\n");
> + return 0;
> + }
> +
> + for (i = 0; i < MMC_ERR_MAX; i++) {
> + if (desc[i])
> + seq_printf(file, "# %s:\t %d\n",
> + desc[i], host->err_stats[i]);
> + }
> +
> + return 0;
> +}
> +
> +static int mmc_err_stats_open(struct inode *inode, struct file *file)
> +{
> + return single_open(file, mmc_err_stats_show, inode->i_private);
> +}
> +
> +static ssize_t mmc_err_stats_write(struct file *filp, const char __user *ubuf,
> + size_t cnt, loff_t *ppos)
> +{
> + struct mmc_host *host = filp->f_mapping->host->i_private;
> +
> + if (!host)
> + return -EINVAL;
> +
> + pr_debug("%s: Resetting MMC error statistics\n", __func__);
> + memset(host->err_stats, 0, sizeof(host->err_stats));
> +
> + return cnt;
> +}
> +
> +static const struct file_operations mmc_err_stats_fops = {
> + .open = mmc_err_stats_open,
> + .read = seq_read,
> + .write = mmc_err_stats_write,
> +};
> +
> void mmc_add_host_debugfs(struct mmc_host *host)
> {
> struct dentry *root;
> @@ -236,6 +312,11 @@ void mmc_add_host_debugfs(struct mmc_host *host)
> debugfs_create_file_unsafe("clock", S_IRUSR | S_IWUSR, root, host,
> &mmc_clock_fops);
>
> + debugfs_create_file("err_state", 0600, root, host,
> + &mmc_err_state);

Please, let's drop err_state for now

> + debugfs_create_file("err_stats", 0600, root, host,
> + &mmc_err_stats_fops);
> +
> #ifdef CONFIG_FAIL_MMC_REQUEST
> if (fail_request)
> setup_fault_attr(&fail_default_attr, fail_request);
>