Re: [U-Boot-Users] pci_hose_write_config_{byte,word}_via_dword?

12 Apr 2004

      I have confirmed the problem reported in this list.
When pci_hose_write_config_{byte,word}_via_dword is used
the upper byte is destroied.
If you can access pci device, please execute pci command
as the followings.
# pci w.l 00.0c.00 10 12345600
# pci display 00.0c.00 10
00000010: 12345601 10000000 00000000 00000000
# pci w.b 00.0c.00 13 ff
# pci display 00.0c.00 10
00000010: ff345601 10000000 00000000 00000000 <== GOOD
-----------------------------------------------------------
# pci w.l 00.0c.00 10 12345600
# pci display 00.0c.00 10
00000010: 12345601 10000000 00000000 00000000
# pci w.b 00.0c.00 12 ff
# pci display 00.0c.00 10
00000010: 00ff5601 10000000 00000000 00000000 <== NG
-----------------------------------------------------------
# pci w.l 00.0c.00 10 12345600
# pci display 00.0c.00 10
00000010: 12345601 10000000 00000000 00000000
# pci w.b 00.0c.00 11 ff
# pci display 00.0c.00 10
00000010: 0034ff01 10000000 00000000 00000000 <== NG
-----------------------------------------------------------
# pci w.l 00.0c.00 10 12345600
# pci display 00.0c.00 10
00000010: 12345601 10000000 00000000 00000000
# pci w.w 00.0c.00 10 ffff
# pci display 00.0c.00 10
00000010: 0000ff01 10000000 00000000 00000000 <== NG
How is your result ?
Best regards.
Masami Komiya
Masao Uebayashi wrote:
...
Hello.
Is there anyone successfully using
pci_hose_write_config_{byte,word}_via_dword defined as a macro in
drivers/pci.c?  Or, are you sure what the code there is doing?  When I
tried to use it, writing a byte failed and I used the following code.
I think the current code is just wrong, but I can't explain how it's
wrong since I can't understand the intention of the code. :-)
Masao

#define	__mask(_o, _v)							\
   (_v << ((offset & _o) * 8))
#define	__data(_o, _v)							\
   ((((unsigned long)(val)) & _v) << ((offset & _o) * 8))
#define PCI_WRITE_VIA_DWORD_OP(__size, __type, __offsetmask, __valmask)	\
int pci_hose_write_config_##__size##_via_dword(				\
   struct pci_controller *hose,					\
   pci_dev_t dev,							\
   int offset,							\
   __type val)							\
{									\
   u32 val32;							\
   								\
   if (pci_hose_read_config_dword(hose, dev, offset & ~0x3, &val32) < 0) \
   	return -1;						\
   /* Clear a byte/word in a word. */				\
   val32 &= ~__mask(__offsetmask, __valmask);			\
   /* Fill a cleared byte/word in a word with a byte/word value. */ \
   val32 |= __data(__offsetmask, __valmask);			\
   /* Write the value as a word! */				\
   if (pci_hose_write_config_dword(hose, dev, offset & ~0x3, val32) < 0) \
   	return -1;						\
   								\
   return 0;							\
}

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