Bad VCC with 5V slot and 3.3/5V card

Kimmo Koivisto kimmo.koivisto at surfeu.fi
Thu Mar 3 11:13:55 EST 2005


Hello

I have problem with 3.3/5V PCMCIA card with 5V PCMCIA slot. I posted this to 
the pcmcia-cs.sourceforge.net mailing list, David Hinds suggested that I 
should post this here:

Old laptop with Intel i82365sl B step ISA-to-PCMCIA. 
PCMCIA slot supports only 5 Volt VCC cards. 
Atmel at76c50x wireles card, supports 3.3 Volts and 5 Volts 
of VCC 

Debian 3, 2.6.7 (also tried with 2.6.8.1) vanilla kernel, pcmcia-cs 3.2.5-8 
CONFIG_PCMCIA=m 
 
When I insert the card, i get error message Bad VCC and 
nothing is working. 
 
When I changed to linux/drivers/pcmcia/cs.c from 
 
/* Do power control. We don't allow changes in Vcc. */ 
if (s->socket.Vcc != req->Vcc) 
return CS_BAD_VCC; 
if (req->Vpp1 != req->Vpp2) 
return CS_BAD_VPP; 
s->socket.Vpp = req->Vpp1; 
if (s->ops->set_socket(s, &s->socket)) 
return CS_BAD_VPP; 

to 

/* Do power control. We don't allow changes in Vcc. */ 
// if (s->socket.Vcc != req->Vcc) 
// return CS_BAD_VCC; 
if (req->Vpp1 != req->Vpp2) 
return CS_BAD_VPP; 
s->socket.Vpp = req->Vpp1; 
if (s->ops->set_socket(s, &s->socket)) 
return CS_BAD_VPP; 

, and recompile, everything works OK. So, I guess cs.c 
tries to compare only slot VCC 5V against card VCC 3.3V 
and fails. Maybe it should compare slot VCC 5V against 
card VCC 3.3V or card VCC 5V.


Any ideas?
I'm not subscriber of this list, I would appreciate if you can reply to my 
mail address :)

Regards
Kimmo Koivisto



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