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

[Sajida Bhanu (Temp) (QUIC)]

Hi,

Thanks for the review.

Please find the inline comments.

Thanks,
Sajida

-----Original Message-----
From: Adrian Hunter <adrian.hunter@xxxxxxxxx> 
Sent: Friday, January 21, 2022 12:40 PM
To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@xxxxxxxxxxx>; Asutosh Das (QUIC) <quic_asutoshd@xxxxxxxxxxx>; ulf.hansson@xxxxxxxxxx; agross@xxxxxxxxxx; bjorn.andersson@xxxxxxxxxx; linux-mmc@xxxxxxxxxxxxxxx; linux-arm-msm@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Cc: stummala@xxxxxxxxxxxxxx; vbadigan@xxxxxxxxxxxxxx; Ram Prakash Gupta (QUIC) <quic_rampraka@xxxxxxxxxxx>; Pradeep Pragallapati (QUIC) <quic_pragalla@xxxxxxxxxxx>; sartgarg@xxxxxxxxxxxxxx; nitirawa@xxxxxxxxxxxxxx; sayalil@xxxxxxxxxxxxxx; Liangliang Lu <luliang@xxxxxxxxxxxxxx>; Bao D . Nguyen <nguyenb@xxxxxxxxxxxxxx>
Subject: Re: [PATCH V3 2/4] mmc: debugfs: Add debug fs entry for mmc driver

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

>>>>> first we can check this right,  if it is set then we can go and check err_stats[] to know more on type of error (data /cmd timeout or CRC errors etc.).
Please let me know your opinion on this.( Same as patch set (V3 1/4).

> +	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);
>