Re: [RFC PATCH 0/5]mmc: Soft Command queue implementation for eMMC5.1 device

Jaehoon Chung
2014-12-23T02:39:46Z

Hi, Dong.

On 12/23/2014 11:30 AM, Dong, Chuanxiao wrote:
> Hi Jaehoon,
>
> It is in a draft eMMC5.1 spec. I believe the official eMMC5.1 spec will be released soon.

Thanks~.I want to see the eMMC5.1 spec. :)
I will test this feature with my board.

Best Regards,
Jaehoon Chung

>
> Thanks
> Chuanxiao
>
>> -----Original Message-----
>> From: linux-mmc-owner@vger.kernel.org
>> [mailto:linux-mmc-owner@vger.kernel.org] On Behalf Of Jaehoon Chung
>> Sent: Monday, December 22, 2014 12:56 PM
>> To: Dong, Chuanxiao; linux-mmc@vger.kernel.org
>> Subject: Re: [RFC PATCH 0/5]mmc: Soft Command queue implementation for
>> eMMC5.1 device
>>
>> Hi, Chuanxiao.
>>
>> Was it published for the eMMC5.1 spec?
>>
>> Best Regards,
>> Jaehoon Chung
>>
>> On 12/19/2014 05:04 PM, Chuanxiao Dong wrote:
>>> Hello,
>>>
>>> Seems community already have some implementation for the eMMC5.1
>>> device command queue feature, but that require the eMMC host
>>> controller to support CMDQ. In my platform, I don't have this kind of
>>> eMMC host controller but I have a Samsung eMMC5.1 device which can
>> support the Command queue.
>>>
>>> With this limitation, I have to let eMMC host controller to manually
>>> send the CMD44/45/13/46/47. So in this way, more commands are needed
>>> for an I/O request, more interrupts/schedule are needed in driver.
>>>
>>> Even this way have some more software overhead, but it can still use
>>> the eMMC5.1 device Command queue feature. After test with the iozone
>> command:
>>> "iozone -zec -t 4 -i0 -i2 -F iozonefile1 iozonefile2 iozonefile3
>>> iozonefile4 -+n -I -r 4k -s 500m -O -R -+r -+D" to test random
>>> performance, I saw a performance improvment for random read on my
>> eMMC5.1 device:
>>>
>>> Random read
>>> SW CMDQ: 5544.6
>>> Normal Read: 3993.05
>>>
>>> So I want to send this serial patches as RFC patch for reviewing
>>>
>>>
>>> Chuanxiao Dong (5):
>>> mmc: replace sbc to precmd and add postcmd
>>> mmc: host: add runtime PM for host class dev
>>> mmc: queue: change mqrq_cur and mqrq_pre to mq qdepth
>>> mmc: core: add support for CMDQ feature in MMC Core stack
>>> mmc: sdhci: add SW CMDQ support for CHT SDHCI host
>>>
>>> drivers/mmc/card/block.c | 538
>> ++++++++++++++++++++++++++++++++++++++---
>>> drivers/mmc/card/queue.c | 213 ++++++++--------
>>> drivers/mmc/card/queue.h | 14 +-
>>> drivers/mmc/core/core.c | 78 +++++-
>>> drivers/mmc/core/host.c | 14 ++
>>> drivers/mmc/core/mmc.c | 43 +++-
>>> drivers/mmc/host/dw_mmc.c | 8 +-
>>> drivers/mmc/host/mmci.c | 14 +-
>>> drivers/mmc/host/omap_hsmmc.c | 18 +-
>>> drivers/mmc/host/sdhci-acpi.c | 1 -
>>> drivers/mmc/host/sdhci-pci.c | 1 -
>>> drivers/mmc/host/sdhci.c | 137 +++++++++--
>>> include/linux/mmc/card.h | 3 +
>>> include/linux/mmc/core.h | 5 +-
>>> include/linux/mmc/host.h | 5 +
>>> include/linux/mmc/mmc.h | 21 ++
>>> include/linux/mmc/pm.h | 1 +
>>> include/linux/mmc/sdhci.h | 1 +
>>> 18 files changed, 909 insertions(+), 206 deletions(-)
>>>
>>
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>