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

[Adrian Hunter <adrian.hunter@intel.com>]

On 25/01/2022 20:19, Sajida Bhanu (Temp) (QUIC) wrote:
> Hi,
> 
> Thanks for the review.
> 
> Please find the inline comments.
> 
> Thanks,
> Sajida
> 
> -----Original Message-----
> From: Adrian Hunter <adrian.hunter@intel.com> 
> Sent: Friday, January 21, 2022 12:40 PM
> To: Sajida Bhanu (Temp) (QUIC) <quic_c_sbhanu@quicinc.com>; Asutosh Das (QUIC) <quic_asutoshd@quicinc.com>; ulf.hansson@linaro.org; agross@kernel.org; bjorn.andersson@linaro.org; linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org; linux-kernel@vger.kernel.org
> Cc: stummala@codeaurora.org; vbadigan@codeaurora.org; Ram Prakash Gupta (QUIC) <quic_rampraka@quicinc.com>; Pradeep Pragallapati (QUIC) <quic_pragalla@quicinc.com>; sartgarg@codeaurora.org; nitirawa@codeaurora.org; sayalil@codeaurora.org; Liangliang Lu <luliang@codeaurora.org>; Bao D . Nguyen <nguyenb@codeaurora.org>
> 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@quicinc.com>
>> Signed-off-by: Liangliang Lu <luliang@codeaurora.org>
>> Signed-off-by: Sayali Lokhande <sayalil@codeaurora.org>
>> Signed-off-by: Bao D. Nguyen <nguyenb@codeaurora.org>
>> ---
>>  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).

Please see my comments for patch 1

> 
>> +	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);
>>
>