simple sd card performance bug fix on OMAP

DISCUSSION Stephen Schwarm, CSDP 4 participants 6 messages May 28, 2010 – Jun 10, 2010

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Stephen Schwarm, CSDP

author

2010-05-28 19:40 UTC #0 lore raw

I have not had time to make a formal patch for this but I thought it was significant enough just to send it out. The problem is on omap systems that use omap_hsmmc.c to run sd or mmc cards. If the system you are using has an 8 wire interface, it will only use a one wire interface to 4 wire cards (eg, sd class 4 and sd class 6).

In the file driver/mmc/omap_hsmmc.c in the function omap_hsmmc_probe:
at about line 1739 change:

   if (mmc_slot(host).wires >= 8)
       mmc->caps |= MMC_CAP_8_BIT_DATA;
   else if (mmc_slot(host).wires >= 4)
       mmc->caps |= MMC_CAP_4_BIT_DATA;

to:

   if (mmc_slot(host).wires >= 8)
       mmc->caps |= MMC_CAP_8_BIT_DATA;
   if (mmc_slot(host).wires >= 4)
       mmc->caps |= w;

just delete the word "else". This sets the MMC_CAP_4_BIT_DATA bit on interfaces that have 8 wire interfaces.

We have seen a BIG performance improvement on our systems.

Steve Schwarm

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n:Schwarm, CSDP;Stephen
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email;internet:[email protected]
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Madhusudhan

2010-05-28 19:53 UTC #1 lore raw

Quoted 9 lines

-----Original Message-----
From: [email protected] [mailto:linux-omap- [email protected]] On Behalf Of Stephen Schwarm, CSDP
Sent: Friday, May 28, 2010 2:05 PM
To: [email protected]
Subject: simple sd card performance bug fix on OMAP

Quoted 6 lines

I have not had time to make a formal patch for this but I thought it was significant enough just to send it out. The problem is on omap systems that use omap_hsmmc.c to run sd or mmc cards. If the system you are using has an 8 wire interface, it will only use a one wire interface to 4 wire cards (eg, sd class 4 and sd class 6).

A patch to fix this was already posted on LO by Kishore.

Regards,
Madhu

Quoted 22 lines

In the file driver/mmc/omap_hsmmc.c in the function omap_hsmmc_probe:
at about line 1739 change:
    if (mmc_slot(host).wires >= 8)
        mmc->caps |= MMC_CAP_8_BIT_DATA;
    else if (mmc_slot(host).wires >= 4)
        mmc->caps |= MMC_CAP_4_BIT_DATA;
to:
    if (mmc_slot(host).wires >= 8)
        mmc->caps |= MMC_CAP_8_BIT_DATA;
    if (mmc_slot(host).wires >= 4)
        mmc->caps |= w;
just delete the word "else". This sets the MMC_CAP_4_BIT_DATA bit on interfaces that have 8 wire interfaces.
We have seen a BIG performance improvement on our systems.
Steve Schwarm

Gadiyar, Anand

2010-05-28 19:54 UTC #2 lore raw

In reply to Stephen Schwarm, CSDP

Quoted 22 lines · CSDP

I have not had time to make a formal patch for this but I thought it was significant enough just to send it out. The problem is on omap systems that use omap_hsmmc.c to run sd or mmc cards. If the system you are using has an 8 wire interface, it will only use a one wire interface to 4 wire cards (eg, sd class 4 and sd class 6).
In the file driver/mmc/omap_hsmmc.c in the function omap_hsmmc_probe:
at about line 1739 change:
    if (mmc_slot(host).wires >= 8)
        mmc->caps |= MMC_CAP_8_BIT_DATA;
    else if (mmc_slot(host).wires >= 4)
        mmc->caps |= MMC_CAP_4_BIT_DATA;
to:
    if (mmc_slot(host).wires >= 8)
        mmc->caps |= MMC_CAP_8_BIT_DATA;
    if (mmc_slot(host).wires >= 4)
        mmc->caps |= w;

Quoted 5 lines

just delete the word "else". This sets the MMC_CAP_4_BIT_DATA bit on interfaces that have 8 wire interfaces.
We have seen a BIG performance improvement on our systems.

Thanks for reporting this.

A similar patch was posted a while ago and is currently marked as "awaiting upstream", although it looks like it got lost again.

<https://patchwork.kernel.org/patch/78713/>

- Anand

Madhusudhan

2010-06-02 17:19 UTC #3 lore raw

Quoted 38 lines

-----Original Message-----
From: [email protected] [mailto:linux-omap- [email protected]] On Behalf Of Gadiyar, Anand
Sent: Friday, May 28, 2010 2:55 PM
To: Stephen Schwarm, CSDP; [email protected]
Subject: RE: simple sd card performance bug fix on OMAP
Quoted 22 lines · CSDP
I have not had time to make a formal patch for this but I thought it was significant enough just to send it out. The problem is on omap systems that use omap_hsmmc.c to run sd or mmc cards. If the system you are using has an 8 wire interface, it will only use a one wire interface to 4 wire cards (eg, sd class 4 and sd class 6).
In the file driver/mmc/omap_hsmmc.c in the function omap_hsmmc_probe:
at about line 1739 change:
    if (mmc_slot(host).wires >= 8)
        mmc->caps |= MMC_CAP_8_BIT_DATA;
    else if (mmc_slot(host).wires >= 4)
        mmc->caps |= MMC_CAP_4_BIT_DATA;
to:
    if (mmc_slot(host).wires >= 8)
        mmc->caps |= MMC_CAP_8_BIT_DATA;
    if (mmc_slot(host).wires >= 4)
        mmc->caps |= w;
Quoted 5 lines
just delete the word "else". This sets the MMC_CAP_4_BIT_DATA bit on interfaces that have 8 wire interfaces.
We have seen a BIG performance improvement on our systems.

Quoted 7 lines

Thanks for reporting this.
A similar patch was posted a while ago and is currently marked as "awaiting upstream", although it looks like it got lost again.
<https://patchwork.kernel.org/patch/78713/>

A revised version of the same patch was posted.

https://patchwork.kernel.org/patch/93519/

Tony, Can you please push this?

Regards,
Madhu

Quoted 5 lines

- Anand
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Tony Lindgren

2010-06-10 06:36 UTC #4 lore raw

Quoted 43 lines · Madhusudhan

Quoted 43 lines
-----Original Message-----
From: [email protected] [mailto:linux-omap- [email protected]] On Behalf Of Gadiyar, Anand
Sent: Friday, May 28, 2010 2:55 PM
To: Stephen Schwarm, CSDP; [email protected]
Subject: RE: simple sd card performance bug fix on OMAP
Quoted 22 lines · CSDP
I have not had time to make a formal patch for this but I thought it was significant enough just to send it out. The problem is on omap systems that use omap_hsmmc.c to run sd or mmc cards. If the system you are using has an 8 wire interface, it will only use a one wire interface to 4 wire cards (eg, sd class 4 and sd class 6).
In the file driver/mmc/omap_hsmmc.c in the function omap_hsmmc_probe:
at about line 1739 change:
    if (mmc_slot(host).wires >= 8)
        mmc->caps |= MMC_CAP_8_BIT_DATA;
    else if (mmc_slot(host).wires >= 4)
        mmc->caps |= MMC_CAP_4_BIT_DATA;
to:
    if (mmc_slot(host).wires >= 8)
        mmc->caps |= MMC_CAP_8_BIT_DATA;
    if (mmc_slot(host).wires >= 4)
        mmc->caps |= w;
Quoted 5 lines
just delete the word "else". This sets the MMC_CAP_4_BIT_DATA bit on interfaces that have 8 wire interfaces.
We have seen a BIG performance improvement on our systems.
Thanks for reporting this.
A similar patch was posted a while ago and is currently marked as "awaiting upstream", although it looks like it got lost again.

Quoted 7 lines

Quoted 2 lines
<https://patchwork.kernel.org/patch/78713/>
A revised version of the same patch was posted.
https://patchwork.kernel.org/patch/93519/
Tony, Can you please push this?

This needs to get merged via linux-mmc list.

Regards,

Tony

Madhusudhan

2010-06-10 15:31 UTC #5 lore raw

Quoted 60 lines

-----Original Message-----
From: Tony Lindgren [mailto:[email protected]]
Sent: Thursday, June 10, 2010 1:36 AM
To: Madhusudhan
Cc: 'Gadiyar, Anand'; 'Stephen Schwarm, CSDP'; [email protected]
Subject: Re: simple sd card performance bug fix on OMAP
Quoted 9 lines · Madhusudhan
Quoted 9 lines
-----Original Message-----
From: [email protected] [mailto:linux-omap- [email protected]] On Behalf Of Gadiyar, Anand
Sent: Friday, May 28, 2010 2:55 PM
To: Stephen Schwarm, CSDP; [email protected]
Subject: RE: simple sd card performance bug fix on OMAP
Quoted 3 lines
Quoted 3 lines
Quoted 2 lines · CSDP
I have not had time to make a formal patch for this but I thought it
was
Quoted 1 line
Quoted 1 line
Quoted 1 line
significant enough just to send it out. The problem is on omap
systems
Quoted 2 lines
Quoted 2 lines
Quoted 2 lines
that use omap_hsmmc.c to run sd or mmc cards. If the system you are using has an 8 wire interface, it will only use a one wire interface
to
Quoted 3 lines
Quoted 3 lines
Quoted 3 lines
4 wire cards (eg, sd class 4 and sd class 6).
In the file driver/mmc/omap_hsmmc.c in the function
omap_hsmmc_probe:
Quoted 7 lines
Quoted 7 lines
Quoted 7 lines
at about line 1739 change:
    if (mmc_slot(host).wires >= 8)
        mmc->caps |= MMC_CAP_8_BIT_DATA;
    else if (mmc_slot(host).wires >= 4)
        mmc->caps |= MMC_CAP_4_BIT_DATA;
Quoted 8 lines
Quoted 8 lines
Quoted 8 lines
to:
    if (mmc_slot(host).wires >= 8)
        mmc->caps |= MMC_CAP_8_BIT_DATA;
    if (mmc_slot(host).wires >= 4)
        mmc->caps |= w;
just delete the word "else". This sets the MMC_CAP_4_BIT_DATA bit
on
Quoted 12 lines
Quoted 12 lines
Quoted 4 lines
interfaces that have 8 wire interfaces.
We have seen a BIG performance improvement on our systems.
Thanks for reporting this.
A similar patch was posted a while ago and is currently marked as "awaiting upstream", although it looks like it got lost again.
<https://patchwork.kernel.org/patch/78713/>

Quoted 8 lines

Quoted 5 lines
A revised version of the same patch was posted.
https://patchwork.kernel.org/patch/93519/
Tony, Can you please push this?
This needs to get merged via linux-mmc list.

Sure. We will repost it.

Regards,
Madhu

Quoted 3 lines

Regards,
Tony