Re: [PATCH] mmc: core: add auto bkops support

From: Alex Lemberg
Date: Mon Jun 27 2016 - 07:45:18 EST


Hi Ulf and Adrian,


On 6/27/16, 12:08 PM, "Ulf Hansson" <ulf.hansson@xxxxxxxxxx> wrote:

>[...]
>
>>>> If I am not wrong, in current implementation of runtime suspend,
>>>> the driver stops BKOPS (send HPI) just before sending sleep command,
>>>> see _mmc_suspend(), depends on âMMC_CAP_AGGRESSIVE_PMâ flag.
>>>> In this case, the eMMC device will not have enough time to perform internal
>>>> BKOPS in both â Manual and Auto BKOPS configurations.
>>>>
>>>
>>> ye, so it seems a pre-exiting issue before introducing auto bkops?
>>> I think we can push another patch to improve it but not handling
>>> it for this $SUBJECT, does it sound ok to you?
>>
>> Runtime suspend for eMMC has a default auto-suspend delay of 3 seconds
>> (refer mmc_blk_probe()). Isn't that when auto bkops would happen?
>
>That's correct.
>
>So perhaps we should extend the default auto-suspend delay?

Due to the differences in flash management and technologies,
I suggest to make this value configurable, and not hard coded.
I believe it should be configured per vendor BKOPS needs.
The default value still can be set to 3 seconds, as done todayâ

>
>The SD case actually have the same issue, as I some background
>operations exists there as well.
>
>[...]
>
>Kind regards
>Uffe