pxa2xx PCMCIA timing issue on iPAQ H5550

PATCH In review Milan Plzik 2 participants 5 messages Aug 3, 2007 – Aug 19, 2007

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Milan Plzik

author

2007-08-03 20:22 UTC #0 lore raw

PATCH 1/1 pxa2xx PCMCIA timing issue on iPAQ H5550

Good day,

recently I've been trying to get working PCMCIA interface on H5000
ipaq series, using dual PCMCIA sleeve. So far things work correctly, but I had to do one modification to drivers/pcmcia/pxa2xx_base.c to get the interface working with orinoco gold PCMCIA card (wired pcnet_cs ethernet card worked even without this modification). Patch attached.

The issue has something to do with assert time on PCMCIA bus, but I'm
not really sure what -- I found the working value just by trial&error approach. I'm not sure how is the assert value in pxa2xx_mcxx_asst calculated (I know, simple formula, but the reason why is it calculated that way is not obvious for me), neither that my modification is correct. It just works with iPAQ.

Please include me in Cc, as I'm not subscribed to neither of mailing
lists.

Best regards,
Milan Plzik

Index: drivers/pcmcia/pxa2xx_base.c
===================================================================
RCS file: /cvs/linux/kernel26/drivers/pcmcia/pxa2xx_base.c,v retrieving revision 1.12

pcmcia/pxa2xx_base.c +1 -1

diff -a -u -r1.12 pxa2xx_base.c
@@ -59,7 +59,7 @@
 				     u_int mem_clk_10khz)
 {
 	u_int code = pcmcia_cycle_ns * mem_clk_10khz;
-	return (code / 300000) + ((code % 300000) ? 1 : 0) - 1;
+	return (code / 300000) + ((code % 300000) ? 1 : 0) + 1;
 }
 
 static inline u_int pxa2xx_mcxx_setup(u_int pcmcia_cycle_ns,

Steven Newbury

2007-08-09 15:13 UTC #1 lore raw

Quoted 8 lines · --- Milan Plzik

Good day,
recently I've been trying to get working PCMCIA interface on H5000
ipaq series, using dual PCMCIA sleeve. So far things work correctly, but I had to do one modification to drivers/pcmcia/pxa2xx_base.c to get the interface working with orinoco gold PCMCIA card (wired pcnet_cs ethernet card worked even without this modification). Patch attached.

Quoted 7 lines

The issue has something to do with assert time on PCMCIA bus, but I'm
not really sure what -- I found the working value just by trial&error approach. I'm not sure how is the assert value in pxa2xx_mcxx_asst calculated (I know, simple formula, but the reason why is it calculated that way is not obvious for me), neither that my modification is correct. It just works with iPAQ.

I posted a patch to linux-arm-kernel which reworked the timing code. The existing is/was IMHO wrong and this showed up for me with frequency scaling where the code would not keep the PCMCIA timings constant with changes to the core frequency. Here it is:
http://marc.info/?l=linux-arm-kernel&m=116861295404294&w=2

Steve

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Milan Plzik

author

2007-08-16 09:29 UTC #2 lore raw

Quoted 17 lines · Steven Newbury

Quoted 8 lines · --- Milan Plzik
Good day,
recently I've been trying to get working PCMCIA interface on H5000
ipaq series, using dual PCMCIA sleeve. So far things work correctly, but I had to do one modification to drivers/pcmcia/pxa2xx_base.c to get the interface working with orinoco gold PCMCIA card (wired pcnet_cs ethernet card worked even without this modification). Patch attached.
Quoted 7 lines
The issue has something to do with assert time on PCMCIA bus, but I'm
not really sure what -- I found the working value just by trial&error approach. I'm not sure how is the assert value in pxa2xx_mcxx_asst calculated (I know, simple formula, but the reason why is it calculated that way is not obvious for me), neither that my modification is correct. It just works with iPAQ.

Quoted 5 lines

I posted a patch to linux-arm-kernel which reworked the timing code. The existing is/was IMHO wrong and this showed up for me with frequency scaling where the code would not keep the PCMCIA timings constant with changes to the core frequency. Here it is:
http://marc.info/?l=linux-arm-kernel&m=116861295404294&w=2

I found out that drivers/pcmcia/pxa2xx_base.c from handhelds.org tree
was a bit modified. I tried both vanilla kernel tree and vanilla+this patch -- both worked with pcnet_cs, and neither one with orinoco card. As far as I understand, handhelds.org modification makes use of memory clock instead of cpu clock for calculations. But even when using old handhelds.org driver with modified formulas, orinoco card won't initialize.

I'm not really sure how things should be calculated, I'll try ask
folks who modified the hh.org driverto see what could cause the problems.

Quoted 4 lines

Steve

Milan

Quoted 4 lines

      ___________________________________________________________
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http://uk.docs.yahoo.com/mail/addressguard2.html

Steven Newbury

2007-08-16 23:49 UTC #3 lore raw

Quoted 25 lines · --- Milan Plzik

Quoted 17 lines · Steven Newbury
Quoted 8 lines · --- Milan Plzik
Good day,
recently I've been trying to get working PCMCIA interface on H5000
ipaq series, using dual PCMCIA sleeve. So far things work correctly, but I had to do one modification to drivers/pcmcia/pxa2xx_base.c to get the interface working with orinoco gold PCMCIA card (wired pcnet_cs ethernet card worked even without this modification). Patch attached.
Quoted 7 lines
The issue has something to do with assert time on PCMCIA bus, but I'm
not really sure what -- I found the working value just by trial&error approach. I'm not sure how is the assert value in pxa2xx_mcxx_asst calculated (I know, simple formula, but the reason why is it calculated that way is not obvious for me), neither that my modification is correct. It just works with iPAQ.
Quoted 3 lines
I posted a patch to linux-arm-kernel which reworked the timing code. The existing is/was IMHO wrong and this showed up for me with frequency scaling where the code would not keep the PCMCIA timings constant with changes to
the
Quoted 2 lines
core frequency. Here it is:
http://marc.info/?l=linux-arm-kernel&m=116861295404294&w=2

Quoted 8 lines

I found out that drivers/pcmcia/pxa2xx_base.c from handhelds.org tree
was a bit modified. I tried both vanilla kernel tree and vanilla+this patch -- both worked with pcnet_cs, and neither one with orinoco card. As far as I understand, handhelds.org modification makes use of memory clock instead of cpu clock for calculations. But even when using old handhelds.org driver with modified formulas, orinoco card won't initialize.

What actually happens? I'm using a spectrum24 and it works fine on my Zaurus SL-C3100. Is it trying to load the firmware? I'm still using 2.6.20, so if something has broken since I don't know about it.

Quoted 4 lines

I'm not really sure how things should be calculated, I'll try ask
folks who modified the hh.org driverto see what could cause the problems.

It is all detailed in the PXA2xx manuals. I did try to enough details in my comments to make sense of the calculation. As was commented on when I posted it, it isn't ideal since it uses divides which are relatively slow on ARMs.

Steve

      ___________________________________________________________

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Milan Plzik

author

2007-08-19 12:04 UTC #4 lore raw

Quoted 35 lines · Steven Newbury

Quoted 25 lines · --- Milan Plzik
Quoted 17 lines · Steven Newbury
Quoted 8 lines · --- Milan Plzik
Good day,
recently I've been trying to get working PCMCIA interface on H5000
ipaq series, using dual PCMCIA sleeve. So far things work correctly, but I had to do one modification to drivers/pcmcia/pxa2xx_base.c to get the interface working with orinoco gold PCMCIA card (wired pcnet_cs ethernet card worked even without this modification). Patch attached.
Quoted 7 lines
The issue has something to do with assert time on PCMCIA bus, but I'm
not really sure what -- I found the working value just by trial&error approach. I'm not sure how is the assert value in pxa2xx_mcxx_asst calculated (I know, simple formula, but the reason why is it calculated that way is not obvious for me), neither that my modification is correct. It just works with iPAQ.
Quoted 3 lines
I posted a patch to linux-arm-kernel which reworked the timing code. The existing is/was IMHO wrong and this showed up for me with frequency scaling where the code would not keep the PCMCIA timings constant with changes to
the
Quoted 2 lines
core frequency. Here it is:
http://marc.info/?l=linux-arm-kernel&m=116861295404294&w=2
Quoted 8 lines
I found out that drivers/pcmcia/pxa2xx_base.c from handhelds.org tree
was a bit modified. I tried both vanilla kernel tree and vanilla+this patch -- both worked with pcnet_cs, and neither one with orinoco card. As far as I understand, handhelds.org modification makes use of memory clock instead of cpu clock for calculations. But even when using old handhelds.org driver with modified formulas, orinoco card won't initialize.

Quoted 3 lines

What actually happens? I'm using a spectrum24 and it works fine on my Zaurus SL-C3100. Is it trying to load the firmware? I'm still using 2.6.20, so if something has broken since I don't know about it.

The orinoco_cs driver fails to initialize the card, it doesn't read
proper value from SWSUPPORT0 register (or something like that, I don't remember exactly). Driver sets some magic value there and expects to read it back correctly, but that doesn't happen.

Quoted 8 lines

Quoted 5 lines
I'm not really sure how things should be calculated, I'll try ask
folks who modified the hh.org driverto see what could cause the problems.
It is all detailed in the PXA2xx manuals. I did try to enough details in my comments to make sense of the calculation. As was commented on when I posted it, it isn't ideal since it uses divides which are relatively slow on ARMs.

Err, I did not mean your code, but handhelds.org one:). I need to ask
why it has been changed to the actual state -- precisely why it doesn't use pxa core frequency, but memclk.

Quoted 5 lines

Steve

Milan

Quoted 2 lines

      ___________________________________________________________ 
Want ideas for reducing your carbon footprint? Visit Yahoo! For Good http://uk.promotions.yahoo.com/forgood/environment.html