24 Apr
2008
24 Apr
'08
4:45 p.m.
In message 1208236923.3656.15.camel@localhost.localdomain you wrote:
Current flush_cache code does
- clean the dcache with dcbst, but not invalidate dcache
- invalidate icache
This patch use the dcbf instead of dcbst to have stronger semantic, clean the dcache and invalidate dcache.
On which processors did you test the changes? I have some unclear memories of dcbf having problems on for example MPC8xx ?
We have two options:
- Separate functions for them like linux kernel. A. clean dcache (dcbst) for DMA_TO_DEVICE B. invalidate dcache (dcbi) for DMA_FROM_DEVICE C. flush dcache (dcbf) for DMA_BIDIRECTIONAL.
- Make current flush_cache stronger semanctic. use the dcbf instead of dcbst.
Which one is better? or you have better option? Please suggest.
We discussed this a bit on IRC; Kumar suggested to go for 1., and I agree.
Best regards,
Wolfgang Denk
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de
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