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Subject: Re: [PATCH] EDAC, ghes: use CPER module handles to locate DIMMs
To:     wufan <wufan@codeaurora.org>
Cc:     mchehab@kernel.org, bp@alien8.de, baicar.tyler@gmail.com,
        linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org
References: <1535567632-18089-1-git-send-email-wufan@codeaurora.org>
 <c70fa799-bc9f-64c8-e151-088ca8c3ed3e@arm.com>
 <000f01d4406f$6ce8f160$46bad420$@codeaurora.org>
From:   James Morse <james.morse@arm.com>
Message-ID: <1ac15a80-6f9a-cf9d-8e79-37d10549a4ca@arm.com>
Date:   Thu, 30 Aug 2018 17:32:08 +0100
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Hi Fan,

On 30/08/18 15:40, wufan wrote:
>>> @@ -327,12 +349,20 @@ void ghes_edac_report_mem_error(int sev,
>> struct cper_sec_mem_err *mem_err)
>>>  		p += sprintf(p, "bit_pos:%d ", mem_err->bit_pos);
>>>  	if (mem_err->validation_bits &
>> CPER_MEM_VALID_MODULE_HANDLE) {
>>>  		const char *bank = NULL, *device = NULL;
>>> +		int index = -1;
>>> +
>>>  		dmi_memdev_name(mem_err->mem_dev_handle, &bank,
>> &device);
>>
>>> +		p += sprintf(p, "DIMM DMI handle: 0x%.4x ",
>>> +			     mem_err->mem_dev_handle);
>>>  		if (bank != NULL && device != NULL)
>>>  			p += sprintf(p, "DIMM location:%s %s ", bank, device);
>>> -		else
>>> -			p += sprintf(p, "DIMM DMI handle: 0x%.4x ",
>>> -				     mem_err->mem_dev_handle);
>>
>> Why do we now print the handle every time? The handle is pretty
>> meaningless, it can only be used to find the location-strings, if we get those
>> we print them instead.
> 
> For ghes_edac the bank/device is informational, and nothing would go wrong
> if the bank/device numbers are the same as another entry. But the handle
> is now critical for DIMM lookup, thus pull it out.

Is printing the handle to the kernel log critical?

I'd expect something collecting errors to read from sysfs, not dmesg. I thought
the whole point here was to update the per-dimm counters in sysfs.


Thanks,

James