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Date: Wed, 10 Jan 2001 15:55:04 -0800
From: Alice Hennessy <ahennessy@mvista.com>
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To: =?iso-8859-1?Q?St=E9phane?= Laroche <stephane.laroche@colubris.com>,
   mtd@infradead.org, ahennessy@mvista.com
Subject: Re: CFI problems with 32bit bus and 4 devices
References: <3A5CB4C3.41FC20D1@colubris.com> <3A5CF18A.3DEAE71E@mvista.com>
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Alice Hennessy wrote:

> Stéphane Laroche wrote:
>
> > Hi,
> >
> > I've just updated to the latest CVS and my CFI AMD chips are not
> > accessible anymore.
> >
> > I lokked briefly into it and saw that the cfi->interleave and
> > cfi->device_type were removed from offset calculations when accessing
> > the devices.
> >
> > So, for my setup, which has 4 x16 devices on a 32 bit bus (AMDs),  the
> > CFI query structure is located at offsets 0x80, 0x88, 0x90, etc.
> >
> > cfi_read_query()  uses only the buswidth to calculate the offset, which
> > is not general enough (it used to be like that before I played with the
> > code a bit last summer).  It's obviously wrong in my case ( 0x10 << 2 !=
> > 0x80 ).
> >
> > Rewriting cfi_read_query like this made the CFI query structure
> > readable:
> >
> > static inline __u8 cfi_read_query(struct map_info *map, __u32 base,
> > __u32 addr)
> > {
> >     struct cfi_private *cfi = map->fldrv_priv;
> >     addr *= cfi->interleave * cfi->device_type;  /* instead of addr <<
> > (buswidth / 2) */
> >     if (cfi_buswidth_is_1()) {
> >         return map->read8(map, base + addr);
> >     } else if (cfi_buswidth_is_2()) {
> >         return cfi16_to_cpu(map->read16(map, base + addr));
> >     } else if (cfi_buswidth_is_4()) {
> >         return cfi32_to_cpu(map->read32(map, base + addr));
> >     } else {
> >         return 0;
> >     }
> > }
> >
> > With this change, the chips are now properly recognized.  But I can't
> > still not use them (reads are wrong), so I think I have to look at
> > cfi_cmdset_002.c to bring back the use of cfi->interleave in some
> > calculations...
> >
> > Any comments?  Is it possible that I'm the only one using that kind of
> > geometry?
> >
> > -Stephane
> >
> > To unsubscribe, send "unsubscribe mtd" to majordomo@infradead.org
>
> I just ran into the same problem with my one 8x16 intel chip which is set
> up in 8 bit mode.
>
> I think the fix should be:
>
> static inline __u8 cfi_read_query(struct map_info *map, __u32 base, __u32
> query_addr, int int
> erleave, int type)
> {
>         __u32 addr = base + cfi_build_query_addr(query_addr, interleave,
> type);
>
>         if (cfi_buswidth_is_1()) {
>                 return map->read8(map, addr);
>         } else if (cfi_buswidth_is_2()) {
>                 return cfi16_to_cpu(map->read16(map, addr));
>         } else if (cfi_buswidth_is_4()) {
>                 return cfi32_to_cpu(map->read32(map, addr));
>         } else {
>                 return 0;
>         }
> }
>
> with cfi_build_query_addr () the same as cfi_build_cmd_addr():
>
> static inline __u32 cfi_build_query_addr(__u32 cmd_ofs, int interleave, int
> type)
> {
>         return (cmd_ofs * type) * interleave;
> }
>
> So that the address of the query is adjusted for the 8 bit selection of an
> 8x16 chip.
> I think the correct address is taken from the combo of interleave and type
> ( which is correctly set up to be
> CFI_DEVICETYPE_X16  for this configuration).
>
> I think we need to pass in the interleave and type because the
> map->fldrv_priv
> isn't set up before the first query call.
>
> Alice

Nevermind,  better to just put back in the ofs_factor in all the
cfi_read_query calls:

int ofs_factor = cfi->interleave * cfi->device_type;
((unsigned char *)cfi.cfiq)[i] = cfi_read_query(map,base + ((0x10 +
i)*ofs_factor));

I should have checked this change with both my test boards, sorry.

Alice




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