This is the mail archive of the ecos-patches@sources.redhat.com mailing list for the eCos project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: Bug fix in cl_8900a ethernet driver


Laurent Gonzalez wrote:

It is a good thing to optimise the aligned case, but I don't thing that the performance increase will be significative. The real bottle neck here, is the memory access to the cs8900 that requires more than 100ns for a single 16-bit io write. Even flash devices are faster !

Ugh. I didn't realise that. Still for the sake of argument I've merged Bob K's patch which he mentioned elsewhere with this and applied it.


Bob, one of the reasons I decided to take something more like my version of cs8900a_send (so shoot me, I'm biased ;-)), was because I believe yours wouldn't be right for len==1 in the last iteration of the for loop (it will HAL_WRITE saved_data which would contain the real data in the MSB, not the LSB), as well as just allowing me to merge it more easily :). So have a look at what I've done to check you're happy.

Jifl
--
eCosCentric    http://www.eCosCentric.com/    The eCos and RedBoot experts
--[ "You can complain because roses have thorns, or you ]--
--[  can rejoice because thorns have roses." -Lincoln   ]-- Opinions==mine


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]