From: Linus Walleij <linus.walleij@linaro.org>
To: Ulf Hansson <ulf.hansson@linaro.org>
Cc: linux-mmc <linux-mmc@vger.kernel.org>,
Adrian Hunter <adrian.hunter@intel.com>,
Wolfram Sang <wsa+renesas@sang-engineering.com>,
Shawn Lin <shawn.lin@rock-chips.com>,
Avri Altman <avri.altman@wdc.com>,
Masami Hiramatsu <masami.hiramatsu@linaro.org>,
linux-block <linux-block@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 05/11] mmc: core: Enable eMMC sleep commands to use HW busy polling
Date: Thu, 6 May 2021 14:55:01 +0200 [thread overview]
Message-ID: <CACRpkdY2fScL3jvKoyR1m3+Yxj2=Nj3PPGm1cAqyn3kBS78aow@mail.gmail.com> (raw)
In-Reply-To: <20210504161222.101536-6-ulf.hansson@linaro.org>
On Tue, May 4, 2021 at 6:12 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
> After the eMMC sleep command (CMD5) has been sent, the card start signals
> busy on the DAT0 line, which can be monitored to understand when it's
> allowed to proceed to power off the VCC regulator.
>
> When MMC_CAP_WAIT_WHILE_BUSY isn't supported by the host the DAT0 line
> isn't being monitored for busy completion, but instead we are waiting a
> fixed period of time. The time corresponds to the sleep timeout that is
> specified in the EXT_CSD register of the eMMC card. This is many cases
> suboptimal, as the timeout corresponds to the worst case scenario.
>
> To improve the situation add support for HW busy polling through the
> ->card_busy() host ops, when the host supports this.
>
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Yours,
Linus Walleij
next prev parent reply other threads:[~2021-05-06 12:55 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-04 16:12 [PATCH 00/11] Initital support for new power/perf features for SD cards Ulf Hansson
2021-05-04 16:12 ` [PATCH 01/11] mmc: core: Drop open coding when preparing commands with busy signaling Ulf Hansson
2021-05-06 12:50 ` Linus Walleij
2021-05-07 1:42 ` Shawn Lin
2021-05-04 16:12 ` [PATCH 02/11] mmc: core: Take into account MMC_CAP_NEED_RSP_BUSY for eMMC HPI commands Ulf Hansson
2021-05-06 12:51 ` Linus Walleij
2021-05-07 1:44 ` Shawn Lin
2021-05-04 16:12 ` [PATCH 03/11] mmc: core: Re-structure some code in __mmc_poll_for_busy() Ulf Hansson
2021-05-06 12:52 ` Linus Walleij
2021-05-07 1:48 ` Shawn Lin
2021-05-04 16:12 ` [PATCH 04/11] mmc: core: Extend re-use of __mmc_poll_for_busy() Ulf Hansson
2021-05-06 12:53 ` Linus Walleij
2021-05-07 1:51 ` Shawn Lin
2021-05-04 16:12 ` [PATCH 05/11] mmc: core: Enable eMMC sleep commands to use HW busy polling Ulf Hansson
2021-05-06 12:55 ` Linus Walleij [this message]
2021-05-07 1:52 ` Shawn Lin
2021-05-04 16:12 ` [PATCH 06/11] mmc: core: Prepare mmc_send_cxd_data() to be re-used for additional cmds Ulf Hansson
2021-05-06 12:56 ` Linus Walleij
2021-05-06 13:00 ` Linus Walleij
2021-05-07 7:30 ` Ulf Hansson
2021-05-07 1:53 ` Shawn Lin
2021-05-04 16:12 ` [PATCH 07/11] mmc: core: Drop open coding in mmc_sd_switch() Ulf Hansson
2021-05-06 12:57 ` Linus Walleij
2021-05-07 1:54 ` Shawn Lin
2021-05-04 16:12 ` [PATCH 08/11] mmc: core: Parse the SD SCR register for support of CMD48/49 and CMD58/59 Ulf Hansson
2021-05-06 13:01 ` Linus Walleij
2021-05-07 1:58 ` Shawn Lin
2021-05-04 16:12 ` [PATCH 09/11] mmc: core: Read the SD function extension registers for power management Ulf Hansson
2021-05-06 13:04 ` Linus Walleij
2021-05-07 2:06 ` Shawn Lin
2021-05-07 7:27 ` Ulf Hansson
2021-05-07 7:48 ` Shawn Lin
2021-05-07 11:36 ` Ulf Hansson
2021-05-04 16:12 ` [PATCH 10/11] mmc: core: Read performance enhancements registers for SD cards Ulf Hansson
2021-05-06 13:05 ` Linus Walleij
2021-05-04 16:12 ` [PATCH 11/11] mmc: core: Add support for Power Off Notification " Ulf Hansson
2021-05-06 13:07 ` Linus Walleij
2021-05-07 6:44 ` [PATCH 00/11] Initital support for new power/perf features " Avri Altman
2021-05-07 7:31 ` Ulf Hansson
2021-05-11 10:56 ` Ulf Hansson
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