From: Ludovic BARRE <ludovic.barre@st.com>
To: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
"Adrian Hunter" <adrian.hunter@intel.com>,
"Wolfram Sang" <wsa+renesas@sang-engineering.com>,
"Baolin Wang" <baolin.wang7@gmail.com>,
"Linus Walleij" <linus.walleij@linaro.org>,
"Chaotian Jing" <chaotian.jing@mediatek.com>,
"Shawn Lin" <shawn.lin@rock-chips.com>,
"Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Subject: Re: [PATCH 01/12] mmc: core: Throttle polling rate for CMD6
Date: Wed, 12 Feb 2020 15:24:38 +0100 [thread overview]
Message-ID: <788f33c1-6051-0adf-42da-6f98e69d71c5@st.com> (raw)
In-Reply-To: <CAPDyKFoUe-9HAz1SaCXGUss=GT5JuOVZpZYLmbUFi6Ee34O92g@mail.gmail.com>
Le 2/12/20 à 3:18 PM, Ulf Hansson a écrit :
> On Wed, 12 Feb 2020 at 14:51, Ludovic BARRE <ludovic.barre@st.com> wrote:
>>
>> hi Ulf
>>
>> Le 2/4/20 à 9:54 AM, Ulf Hansson a écrit :
>>> In mmc_poll_for_busy() we loop continuously, either by sending a CMD13 or
>>> by invoking the ->card_busy() host ops, as to detect when the card stops
>>> signaling busy. This behaviour is problematic as it may cause CPU hogging,
>>> especially when the busy signal time reaches beyond a few ms.
>>>
>>> Let's fix the issue by adding a throttling mechanism, that inserts a
>>> usleep_range() in between the polling attempts. The sleep range starts at
>>> 16-32us, but increases for each loop by a factor of 2, up until the range
>>
>> Just to align comment and code: in the code the first usleep range start
>> at 32-64us.
>
> Yeah, good point, thanks. I was trying different values, but forgot to
> update the commit message. :-)
I tested series on mmci, sdmmc variant with/out MMC_CAP_WAIT_WHILE_BUSY
and it seems OK
yes, I reviewing the other patch of series but for this patch is OK.
Reviewed-by: Ludovic Barre <ludovic.barre@st.com>
>
> Other than that, does the change look good to you?
>
> [...]
>
> Kind regards
> Uffe
>
next prev parent reply other threads:[~2020-02-12 14:25 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-04 8:54 [PATCH 00/12] mmc: core: Improve code for polling and HW busy detect Ulf Hansson
2020-02-04 8:54 ` [PATCH 01/12] mmc: core: Throttle polling rate for CMD6 Ulf Hansson
2020-02-12 13:51 ` Ludovic BARRE
2020-02-12 14:18 ` Ulf Hansson
2020-02-12 14:24 ` Ludovic BARRE [this message]
2020-02-04 8:54 ` [PATCH 02/12] mmc: core: Drop unused define Ulf Hansson
2020-02-04 8:54 ` [PATCH 03/12] mmc: core: Extend mmc_switch_status() to rid of __mmc_switch_status() Ulf Hansson
2020-02-04 8:54 ` [PATCH 04/12] mmc: core: Drop redundant in-parameter to __mmc_switch() Ulf Hansson
2020-02-04 8:54 ` [PATCH 05/12] mmc: core: Split up mmc_poll_for_busy() Ulf Hansson
2020-02-04 8:54 ` [PATCH 06/12] mmc: core: Enable re-use of mmc_blk_in_tran_state() Ulf Hansson
2020-02-04 8:54 ` [PATCH 07/12] mmc: core: Update CMD13 busy check for CMD6 commands Ulf Hansson
2020-02-04 8:54 ` [PATCH 08/12] mmc: core: Convert to mmc_poll_for_busy() for erase/trim/discard Ulf Hansson
2020-02-04 8:54 ` [PATCH 09/12] mmc: core: Drop redundant out-parameter to mmc_send_hpi_cmd() Ulf Hansson
2020-02-04 8:54 ` [PATCH 10/12] mmc: core: Convert to mmc_poll_for_busy() for HPI commands Ulf Hansson
2020-02-04 8:54 ` [PATCH 11/12] mmc: core: Fixup support for HW busy detection " Ulf Hansson
2020-02-04 8:54 ` [PATCH 12/12] mmc: core: Re-work the error path for the eMMC sanitize command Ulf Hansson
2020-02-11 22:29 ` kbuild test robot
2020-02-11 13:17 ` [PATCH 00/12] mmc: core: Improve code for polling and HW busy detect Baolin Wang
2020-02-13 6:23 ` Baolin Wang
2020-02-13 11:08 ` Ulf Hansson
2020-02-13 14:42 ` Ludovic BARRE
2020-02-14 14:21 ` Ulf Hansson
2020-02-18 23:38 ` Ulf Hansson
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