From: oliver+list@schinagl•nl (Olliver Schinagl)
To: linux-arm-kernel@lists•infradead.org
Subject: [linux-sunxi] [PATCH 3/3] mmc: sunxi: use controller automatic clock gating.
Date: Wed, 12 Aug 2015 15:19:20 +0200 [thread overview]
Message-ID: <55CB47D8.4010207@schinagl.nl> (raw)
In-Reply-To: <55CB3D92.6040403@redhat.com>
Hey,
On 12-08-15 14:35, Hans de Goede wrote:
> Hi,
>
> On 12-08-15 14:23, Michal Suchanek wrote:
>> When core does not set the MMC_QUIRK_BROKEN_CLK_GATING flag enable
>> automatic hardware controlled clock gating on the mmc interface.
>>
>> Signed-off-by: Michal Suchanek <hramrach@gmail•com>
>
> In general this looks good, but I wonder how intensively this has
> been tested ?
It doesn't matter actually, it took some time longer, but the mmc still
craps out even with Michal's 3 patches. I'll revert hans's earlier patch
again and do a bit more extensive testing.
> Also given the long latencies when using manual
> clock on/off support, have you done any testing to check what
> sort of latencies this adds, e.g. Both with and without
> the patch, dump all the filesystem caches:
>
> echo 3 > /proc/sys/vm/drop_caches
>
> And then do:
>
> time cat /some/small/file/on/the/sdcard
>
> Do this at least 3 time both with and without the patch, and see
> if there are any noticable differences ?
>
> Regards,
>
> Hans
>
>
>
>> ---
>> drivers/mmc/host/sunxi-mmc.c | 7 ++++++-
>> 1 file changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/sunxi-mmc.c b/drivers/mmc/host/sunxi-mmc.c
>> index f808a02..443cab5 100644
>> --- a/drivers/mmc/host/sunxi-mmc.c
>> +++ b/drivers/mmc/host/sunxi-mmc.c
>> @@ -601,8 +601,13 @@ static int sunxi_mmc_oclk_onoff(struct
>> sunxi_mmc_host *host, u32 oclk_en)
>> rval = mmc_readl(host, REG_CLKCR);
>> rval &= ~(SDXC_CARD_CLOCK_ON | SDXC_LOW_POWER_ON);
>>
>> - if (oclk_en)
>> + if (oclk_en) {
>> rval |= SDXC_CARD_CLOCK_ON;
>> + if (!host->mmc->card ||
>> + !(host->mmc->card->quirks & MMC_QUIRK_BROKEN_CLK_GATING))
>> +
>> + rval |= SDXC_LOW_POWER_ON;
>> + }
>>
>> start = jiffies;
>> end = start + msecs_to_jiffies(750);
>>
>
next prev parent reply other threads:[~2015-08-12 13:19 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-12 12:10 [PATCH 0/3] misc MMC fixes Michal Suchanek
2015-08-12 12:23 ` [PATCH 2/3] mmc: dw_mmc: simplify the SDMMC_CLKEN_LOW_PWR logic Michal Suchanek
2015-08-17 1:55 ` Jaehoon Chung
2015-08-17 5:52 ` Michal Suchanek
2015-08-17 11:26 ` Jaehoon Chung
2015-08-17 14:42 ` Alim Akhtar
2015-08-17 14:55 ` Michal Suchanek
2015-08-17 16:21 ` Alim Akhtar
2015-08-12 12:23 ` [PATCH resend 1/3] mmc: sunxi: fix timeout in sunxi_mmc_oclk_onoff michal.suchanek at ruk.cuni.cz
2015-08-12 12:32 ` Hans de Goede
2015-08-12 12:40 ` [linux-sunxi] " Olliver Schinagl
2015-08-12 13:04 ` Michal Suchanek
2015-08-12 13:29 ` [PATCH v3 " Michal Suchanek
2015-08-12 14:49 ` [linux-sunxi] " Hans de Goede
2015-08-25 12:06 ` Ulf Hansson
2015-08-12 12:23 ` [PATCH 3/3] mmc: sunxi: use controller automatic clock gating Michal Suchanek
2015-08-12 12:35 ` [linux-sunxi] " Hans de Goede
2015-08-12 12:53 ` Michal Suchanek
2015-08-12 13:19 ` Olliver Schinagl [this message]
2015-08-12 13:37 ` Michal Suchanek
2015-08-12 14:57 ` Olliver Schinagl
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