* Re: Sending one byte transfers using SPI bus with linux-2.6.32
[not found] ` <E4CEDCEF-66BE-4C94-A27D-5088882A1E0C-ee4meeAH724@public.gmane.org>
@ 2011-03-04 15:59 ` Grant Likely
[not found] ` <7974B5C3-662C-40A9-AB44-722A84190886@mac.com>
0 siblings, 1 reply; 5+ messages in thread
From: Grant Likely @ 2011-03-04 15:59 UTC (permalink / raw)
To: Elvis Dowson, SPI Developer Mailing List
Elvis Dowson <elvis.dowson-ee4meeAH724@public.gmane.org> wrote:
>Hi,
>I modified the spidev_test.c program and I find that when sending data,
>I have to specific a minimum transfer length of 2, for a message.
>
>If I specify an array size of 1, no transfer takes place.
What backend spi master driver/device are you using? Single byte transfers should work. It may be a bug/limitation of the driver.
g.
--
Sent from my Android phone with K-9 Mail. Please excuse my brevity.
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What You Don't Know About Data Connectivity CAN Hurt You
This paper provides an overview of data connectivity, details
its effect on application quality, and explores various alternative
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Sending one byte transfers using SPI bus with linux-2.6.32
[not found] ` <7974B5C3-662C-40A9-AB44-722A84190886-ee4meeAH724@public.gmane.org>
@ 2011-03-04 19:38 ` Kevyn-Alexandre Paré
[not found] ` <1299268583.2338.6.camel@andromeda>
0 siblings, 1 reply; 5+ messages in thread
From: Kevyn-Alexandre Paré @ 2011-03-04 19:38 UTC (permalink / raw)
To: Elvis Dowson; +Cc: SPI Developer Mailing List
Hi Elvis,
I have done some test without problem with spidev_test.c and was sending
tx[1].
Best Regards,
Kevyn-Alexandre Paré
On Fri, 2011-03-04 at 20:58 +0400, Elvis Dowson wrote:
> Elvis Dowson
------------------------------------------------------------------------------
What You Don't Know About Data Connectivity CAN Hurt You
This paper provides an overview of data connectivity, details
its effect on application quality, and explores various alternative
solutions. http://p.sf.net/sfu/progress-d2d
_______________________________________________
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* Re: Sending one byte transfers using SPI bus with linux-2.6.32
[not found] ` <1299268583.2338.6.camel@andromeda>
@ 2011-03-04 19:58 ` Kevyn-Alexandre Paré
[not found] ` <B9012B37-7DAE-4D5D-B3F5-FFD675C89648@mac.com>
0 siblings, 1 reply; 5+ messages in thread
From: Kevyn-Alexandre Paré @ 2011-03-04 19:58 UTC (permalink / raw)
To: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f
Just to mention that I was with OMAP 3530
2.6.34 and know 2.6.36 (gumstix overo)
kap
On Fri, 2011-03-04 at 14:56 -0500, Kevyn-Alexandre Paré wrote:
> Just to mention that I was with OMAP 3530
> 2.6.34 and know 2.6.36 (gumstix overo)
>
> kap
------------------------------------------------------------------------------
What You Don't Know About Data Connectivity CAN Hurt You
This paper provides an overview of data connectivity, details
its effect on application quality, and explores various alternative
solutions. http://p.sf.net/sfu/progress-d2d
_______________________________________________
spi-devel-general mailing list
spi-devel-general@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/spi-devel-general
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Sending one byte transfers using SPI bus with linux-2.6.32
[not found] ` <B9012B37-7DAE-4D5D-B3F5-FFD675C89648-ee4meeAH724@public.gmane.org>
@ 2011-03-04 20:56 ` Kevyn-Alexandre Paré
[not found] ` <1BCF7F7D-8E99-41A1-B134-9D7B478BC900@mac.com>
0 siblings, 1 reply; 5+ messages in thread
From: Kevyn-Alexandre Paré @ 2011-03-04 20:56 UTC (permalink / raw)
To: Elvis Dowson; +Cc: SPI Developer Mailing List
simply t[1] I reuse -s option just diff it with the original
http://pastebin.com/Ys6wMD1S
Did you try later version of kernel?
Kevyn-Alexandre Paré
On Sat, 2011-03-05 at 00:11 +0400, Elvis Dowson wrote:
> On Mar 4, 2011, at 11:58 PM, Kevyn-Alexandre Paré wrote:
>
> > Just to mention that I was with OMAP 3530
> > 2.6.34 and know 2.6.36 (gumstix overo)
>
> Ok, 2.6.32 didn't work for 1 byte transfers.
>
> Do you have a sample code snippet that you can share, or was it just putting tx[1] and re-using the spidev_test.c example.
>
> Elvis Dowson
------------------------------------------------------------------------------
What You Don't Know About Data Connectivity CAN Hurt You
This paper provides an overview of data connectivity, details
its effect on application quality, and explores various alternative
solutions. http://p.sf.net/sfu/progress-d2d
_______________________________________________
spi-devel-general mailing list
spi-devel-general@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/spi-devel-general
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: Sending one byte transfers using SPI bus with linux-2.6.32
[not found] ` <1BCF7F7D-8E99-41A1-B134-9D7B478BC900-ee4meeAH724@public.gmane.org>
@ 2011-03-08 1:00 ` Kevyn-Alexandre Paré
0 siblings, 0 replies; 5+ messages in thread
From: Kevyn-Alexandre Paré @ 2011-03-08 1:00 UTC (permalink / raw)
To: Elvis Dowson; +Cc: SPI Developer Mailing List
A simple git diff should have save us some time ;)
git diff v2.6.32 v2.6.36 -- spidev_test.c
warning: refname 'v2.6.32' is ambiguous.
diff --git a/Documentation/spi/spidev_test.c
b/Documentation/spi/spidev_test.c
index 10abd37..16feda9 100644
--- a/Documentation/spi/spidev_test.c
+++ b/Documentation/spi/spidev_test.c
@@ -58,7 +58,7 @@ static void transfer(int fd)
};
ret = ioctl(fd, SPI_IOC_MESSAGE(1), &tr);
- if (ret == 1)
+ if (ret < 1)
pabort("can't send spi message");
for (ret = 0; ret < ARRAY_SIZE(tx); ret++) {
-- kap
On Sun, 2011-03-06 at 21:45 +0400, Elvis Dowson wrote:
> Hi,
> The problem was in the spidev_test.c program itself, in linux-2.6.32.
>
> After applying the following patch taken from linux-2.6.34, 1 byte transfers work.
>
> http://git.kernel.org/?p=linux/kernel/git/longterm/linux-2.6.34.y.git;a=blobdiff;f=Documentation/spi/spidev_test.c;h=16feda9014692a87a4996bf51d759ab9e7500ee5;hp=10abd3773e49122aab0dfad27f7cb2c91b8d5d08;hb=95b1ed2ac7ffe3205afc6f5a20320fbdb984da92;hpb=dda04c7bcf58cb02ac796beb1cf483aa5277f2af
>
> Elvis Dowson
------------------------------------------------------------------------------
What You Don't Know About Data Connectivity CAN Hurt You
This paper provides an overview of data connectivity, details
its effect on application quality, and explores various alternative
solutions. http://p.sf.net/sfu/progress-d2d
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