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Subject: Re: [PATCH 2/2] mmc: core: Add no single read retries
From:   Adrian Hunter <adrian.hunter@intel.com>
To:     DooHyun Hwang <dh0421.hwang@samsung.com>,
        linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org, ulf.hansson@linaro.org,
        robh+dt@kernel.org, axboe@kernel.dk, satyat@google.com,
        ebiggers@google.com, gustavoars@kernel.org
Cc:     grant.jung@samsung.com, jt77.jang@samsung.com,
        junwoo80.lee@samsung.com, jangsub.yi@samsung.com,
        sh043.lee@samsung.com, cw9316.lee@samsung.com,
        sh8267.baek@samsung.com, wkon.kim@samsung.com
References: <20210217052239.13780-1-dh0421.hwang@samsung.com>
 <CGME20210217053521epcas1p2aa80cae5d52f30c8c8882f44abe8045c@epcas1p2.samsung.com>
 <20210217052239.13780-3-dh0421.hwang@samsung.com>
 <4035139d-7850-8460-f069-06fc61d13039@intel.com>
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Date:   Wed, 17 Feb 2021 08:00:36 +0200
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On 17/02/21 7:46 am, Adrian Hunter wrote:
> On 17/02/21 7:22 am, DooHyun Hwang wrote:
>> This makes to handle read errors faster by not retrying
>> multiple block read(CMD18) errors with single block reads(CMD17).
>>
>> On some bad SD Cards that have problem with read operations,
>> it is not helpful to retry multiple block read errors with
>> several single block reads, and it is delayed to treat read
>> operations as I/O error as much as retrying single block reads.
> 
> If the issue is that it takes too long, then maybe it would be better to get
> mmc_blk_read_single() to give up after a certain amount of time.
> 

So that a device property would not be needed I mean.  Then everyone would
benefit.