diff options
author | Clemens Ladisch <clemens@ladisch.de> | 2011-01-13 10:12:17 +0100 |
---|---|---|
committer | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2011-01-13 15:48:29 +0100 |
commit | 1427130425c1239d977e8891c3a8923f53a6e352 (patch) | |
tree | 940207bbaf155d7ed36c6b8fab201dae6773ec1f /drivers/cpufreq | |
parent | 410cf2bd3dc6ec1ed9e1b36b25b9d7aa927ed14e (diff) |
firewire: ohci: fix compilation on arches without PAGE_KERNEL_RO
PAGE_KERNEL_RO is not available on all architectures, so its use
in the new AR code broke compilation on sparc64.
Because the read-only mapping was just a debugging aid, just use
PAGE_KERNEL instead.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
James Bottomley wrote:
> On Thu, 2011-01-13 at 08:27 +0100, Clemens Ladisch wrote:
>> firewire: ohci: fix compilation on arches without PAGE_KERNEL_RO, e.g. sparc
>>
>> PAGE_KERNEL_RO is not available on all architectures, so its use in the
>> new AR code broke compilation on sparc64.
>>
>> Because the R/O mapping is only used to catch drivers that try to write
>> to the reception buffer and not actually required for correct operation,
>> we can just use a normal PAGE_KERNEL mapping where _RO is not available.
[...]
>> +/*
>> + * For archs where PAGE_KERNEL_RO is not supported;
>> + * mapping the AR buffers readonly for the CPU is just a debugging aid.
>> + */
>> +#ifndef PAGE_KERNEL_RO
>> +#define PAGE_KERNEL_RO PAGE_KERNEL
>> +#endif
>
> This might cause interesting issues on sparc64 if it ever acquired a
> PAGE_KERNEL_RO. Sparc64 has extern pgprot_t for it's PAGE_KERNEL types
> rather than #defines, so the #ifdef check wouldn't see this.
>
> I think either PAGE_PROT_RO becomes part of our arch API (so all
> architectures are forced to add it), or, if it's not part of the API,
> ohci isn't entitled to use it. The latter seems simplest since you have
> no real use for write protection anyway.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Diffstat (limited to 'drivers/cpufreq')
0 files changed, 0 insertions, 0 deletions