From: Adrian Hunter <adrian.hunter@intel.com>
To: "Christian Löhle" <CLoehle@hyperstone.com>,
"Avri Altman" <Avri.Altman@wdc.com>,
"Michael Wu" <michael@allwinnertech.com>,
"ulf.hansson@linaro.org" <ulf.hansson@linaro.org>,
"beanhuo@micron.com" <beanhuo@micron.com>,
"porzio@gmail.com" <porzio@gmail.com>
Cc: "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
allwinner-opensource-support
<allwinner-opensource-support@allwinnertech.com>
Subject: Re: [PATCH] mmc: block: enable cache-flushing when mmc cache is on
Date: Wed, 16 Mar 2022 18:05:52 +0200 [thread overview]
Message-ID: <a1230f11-a2dd-1959-5444-28c57d3babf6@intel.com> (raw)
In-Reply-To: <7ec0cf3e316a4ed9987962b4cbf01604@hyperstone.com>
On 16.3.2022 16.46, Christian Löhle wrote:
>> So we are not going to let the block layer know about SD cache?
>> Or is it a separate change?
>
> I have some code for this laying around, but as it requires reading, parsing and writing Function Registers,
> in particular PEH, it's a lot of boilerplate code to get the functionality, but I'll clean it up and send a patch in the coming weeks.
>
We have the sd cache flush. We would presumably just need to call blk_queue_write_cache()
for the !mmc_card_mmc(card) case e.g.
if (mmc_has_reliable_write(card)) {
md->flags |= MMC_BLK_REL_WR;
enable_fua = true;
}
if (mmc_cache_enabled(card->host))
enable_cache = true;
blk_queue_write_cache(md->queue.queue, enable_cache, enable_fua);
Avri, were you objecting to that?
>
>
>
>
> From: Adrian Hunter <adrian.hunter@intel.com>
> Sent: Wednesday, March 16, 2022 12:28 PM
> To: Avri Altman; Michael Wu; ulf.hansson@linaro.org; beanhuo@micron.com; porzio@gmail.com
> Cc: linux-mmc@vger.kernel.org; linux-kernel@vger.kernel.org; allwinner-opensource-support
> Subject: Re: [PATCH] mmc: block: enable cache-flushing when mmc cache is on
>
> On 16.3.2022 13.09, Avri Altman wrote:
>>> Hi Avril & Adrian,
>>> Thanks for your efforts. Could we have an agreement now --
>>>
>>> 1. enabling-cache and cmd23/reliable-write should be independent;
>>>
>>> Here's what I found in the spec JESD84-B51:
>>> > 6.6.31 Cache
>>> > Caching of data shall apply only for the single block
>>> > read/write(CMD17/24), pre-defined multiple block
>>> > read/write(CMD23+CMD18/25) and open ended multiple block
>>> > read/write(CMD18/25+CMD12) commands and excludes any other access
>>> > e.g., to the register space(e.g., CMD6).
>>> Which means with CMD18/25+CMD12 (without using CMD23), the cache can
>>> also be enabled. Maybe this could be an evidence of the independence
>>> between enabling-cache and cmd23/reliable-write?
>> Acked-by: Avri Altman <avri.altman@wdc.com>
>>
>> Thanks,
>> Avri
>>
>>>
>>> 2. We don't consider supporting SD in this change.
>>>
>>> > On 14/03/2022 19:10, Avri Altman wrote:
>>> >> Here is what our SD system guys wrote:
>>> >> " In SD we don’t support reliable write and this eMMC driver may not
>>> >> be utilizing the cache feature we added in SD5.0.
>>> >> The method of cache flush is different between SD and eMMC."
>>> >>
>>> >> So adding SD seems to be out of scope of this change.
>>>
>>> Is there anything else I can do about this patch? Thanks again.
>
> So we are not going to let the block layer know about SD cache?
> Or is it a separate change?
> =
> Hyperstone GmbH | Reichenaustr. 39a | 78467 Konstanz
> Managing Director: Dr. Jan Peter Berns.
> Commercial register of local courts: Freiburg HRB381782
>
next prev parent reply other threads:[~2022-03-16 16:08 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-12 4:43 [PATCH] mmc: block: enable cache-flushing when mmc cache is on Michael Wu
2022-03-14 6:54 ` Adrian Hunter
2022-03-14 9:20 ` Michael Wu
2022-03-14 9:37 ` Avri Altman
2022-03-16 9:54 ` Michael Wu
2022-03-16 11:09 ` Avri Altman
2022-03-16 11:28 ` Adrian Hunter
2022-03-16 14:46 ` Christian Löhle
2022-03-16 16:05 ` Adrian Hunter [this message]
2022-03-17 9:14 ` Ulf Hansson
2022-03-24 11:27 ` Ulf Hansson
2022-03-25 5:45 ` Michael Wu
2022-03-25 10:13 ` Ulf Hansson
2022-03-28 10:11 ` Michael Wu
2022-03-28 11:38 ` Ulf Hansson
2022-03-29 9:08 ` Michael Wu
2022-03-29 9:53 ` Ulf Hansson
2022-03-27 8:09 ` Avri Altman
2022-03-14 11:10 ` Avri Altman
2022-03-14 7:26 ` Avri Altman
2022-03-14 10:32 ` Adrian Hunter
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