s3c2410_udc: 2440 dual packet workaround

PATCH Superseded Vasily Khoruzhick 5 participants 8 messages Sep 23, 2009 – Sep 25, 2009 1 message not in the archive

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Vasily Khoruzhick

author

2009-09-23 07:46 UTC #0 lore raw

PATCH 1/5 s3c2410_udc: 2440 dual packet workaround

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David Anders

2009-09-23 19:20 UTC #1 lore raw

PATCH 1/5 s3c2410_udc: 2440 dual packet workaround

Vasily,

i have tried this patch on a number of S3C2440 based systems and found that this patch is not a completely effective solution. if the purpose is to get a solution even if it is an incomplete one, then i'd be ok with this patch, however, i'm not keen on accepting a patch into the main tree with the knowledge that it isn't 100% effective.

Dave Anders

Quoted 16 lines · Vasily Khoruzhick

From: Vasily Khoruzhick <[email protected]>
Subject: [PATCH 1/5] s3c2410_udc: 2440 dual packet workaround
To: "Ben Dooks" <[email protected]>, linux-arm-kernel at lists.infradead.org
Date: Wednesday, September 23, 2009, 2:46 AM
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Vasily Khoruzhick

author

2009-09-23 19:29 UTC #2 lore raw

PATCH 1/5 s3c2410_udc: 2440 dual packet workaround

? ????????? ?? 23 ???????? 2009 22:20:05 ????? David Anders ???????:

Quoted 7 lines

Vasily,
i have tried this patch on a number of S3C2440 based systems and found that
this patch is not a completely effective solution. if the purpose is to get a solution even if it is an incomplete one, then i'd be ok with this patch, however, i'm not keen on accepting a patch into the main tree with the knowledge that it isn't 100% effective.

Hi, Dave

s3c2410_udc driver is almost useless (at least it's very inconvenient) on s3c244x machines without this patch. I think it's much better to have incomplete solution than broken driver.

Btw, I can resend patchset without this patch if maintainer of this driver
thinks that accepting this patch is bad idea.
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A message that is not in the archive (sent off-list or not yet received): [email protected]

Vasily Khoruzhick

author

2009-09-24 19:38 UTC #4 lore raw

PATCH 1/5 s3c2410_udc: 2440 dual packet workaround

? ????????? ?? 24 ???????? 2009 08:11:17 ????? Fabian Godehardt ???????:

Quoted 7 lines

On our 2440 machine i found out that adding a receive handling on the interrupt handler makes the driver work, and in ethernet gadget mode the
pings returned much faster.
Im not realy familiar with the USB layer / protocoll so i'm not sure if
this breaks something else. You might have a look at this patch (it is 2.6.26 against 2.6.31 so maybe it will not apply successfully and you need to take a hand on it).

Your patch works as well with little modification (you used && instead of &). And it seems to be a bit cleaner, it can't stuck in interrupt handler for a while as previous. Would you mind if I submit your patch as part of my patches? I'll add note that you're author of original patch.

Regards
Vasily
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Fabian Godehardt

2009-09-25 04:32 UTC #5 lore raw

PATCH 1/5 s3c2410_udc: 2440 dual packet workaround

Hi Vasily,

Am Donnerstag 24 September 2009 21:38:06 schrieb Vasily Khoruzhick:

Quoted 4 lines

Your patch works as well with little modification (you used && instead of
&). And it seems to be a bit cleaner, it can't stuck in interrupt handler for a while as previous. Would you mind if I submit your patch as part of my patches? I'll add note that you're author of original patch.

I have no problem with it. Please submit it with your patches. Thanks.

Regards,
Fabian Godehardt

Signature · 6 lines

Dipl.-Ing. (FH) Fabian Godehardt, emlix GmbH, http://www.emlix.com
Fon +49 551 30664-0, Fax -11, Bahnhofsallee 1b, 37081 G?ttingen, Germany
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Ben Dooks

2009-09-24 00:27 UTC #6 lore raw

PATCH 1/5 s3c2410_udc: 2440 dual packet workaround

In reply to David Anders

Quoted 5 lines · David Anders

Vasily,
i have tried this patch on a number of S3C2440 based systems and found that this patch is not a completely effective solution. if the purpose is to get a solution even if it is an incomplete one, then i'd be ok with this patch, however, i'm not keen on accepting a patch into the main tree with the knowledge that it isn't 100% effective.
Dave Anders

I think that if this is afix that makes the code mostly work then there really should be some form of note in the code that says that this fix is a mostly effective form.

Quoted 22 lines

Quoted 16 lines · Vasily Khoruzhick
From: Vasily Khoruzhick <[email protected]>
Subject: [PATCH 1/5] s3c2410_udc: 2440 dual packet workaround
To: "Ben Dooks" <[email protected]>, linux-arm-kernel at lists.infradead.org
Date: Wednesday, September 23, 2009, 2:46 AM
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Signature · 5 lines

-- 
Ben

Q:      What's a light-year?
A:      One-third less calories than a regular year.

Robert Jarzmik

2009-09-23 19:24 UTC #7 lore raw

PATCH 1/5 s3c2410_udc: 2440 dual packet workaround

In reply to Vasily Khoruzhick

Quoted 5 lines · Vasily Khoruzhick

This needs to be examined further. For now, the patch seems to do the trick.
Note that this is not a clean solution by any means, because we might potentially get stuck in that interrupt for quite a while.

Hi Vasily,

That workaround could also freeze the kernel if hardware fails, can't it ?

If there is no better patch found, Wouldn't this patch benefit at least a counter to get out of the interrupt handler if the hardware doesn't behave at the Nth loop ?

Cheers.

--
Robert

Vasily Khoruzhick

author

2009-09-23 19:35 UTC #8 lore raw

PATCH 1/5 s3c2410_udc: 2440 dual packet workaround

? ????????? ?? 23 ???????? 2009 22:24:34 ????? Robert Jarzmik ???????:

Quoted 3 lines

If there is no better patch found, Wouldn't this patch benefit at least a counter to get out of the interrupt handler if the hardware doesn't behave
at the Nth loop ?

Of course, it won't be hard to implement. I'll wait for comments on other 4 patches, fix them and then resend whole patchset.