On 11/27/06, Stefan Richter <[EMAIL PROTECTED]> wrote:
Posted writes are still enabled. phys_dma=0 disables only the physical response unit. You have to change the source if you want to disable posted writes. See the top of ohci_initialize. Should this be a module load parameter too?
Er. I misspoke. What I need is for write requests directed to address 0 to be directed to the asynchronous unit so that I can treat them as regular asynchronous write requests. As the OHCI 1.1 spec says: "Physical requests that are rejected by the PhysicalRequestFilter shall be sent to the AR Request DMA context if the AR Request DMA context is enabled". (5.14.2, page 58) That does appear to be happening: I have an ARM mapping set to begin at 0 and extend some ways along, and I do receive write requests. At first I was simply changing the lines: reg_write(ohci,OHCI1394_PhyReqFilterHiSet, 0xffffffff); reg_write(ohci,OHCI1394_PhyReqFilterLoSet, 0xffffffff); to be 0x0000 0000 instead, but then I paid more attention to the source and saw the phys_dma parameter, which does the same. .... Well, *did*, in 2.6.16. I see that 2.6.18 doesn't write 0 if !phys_dma, it just leaves the values alone, but I guess that's okay since they are set to 0 on reset. Same difference. So that's okay. Uhm, mostly. You should really see the horrors I have created in order to be able to have 5 hosts map the same address range (the custom protocol we're using doesn't use the destination address at all, so it's 0 for everybody). So long ways round, I think the phys_dma parameter is the proper thing for me. And I will try and do some actual thinking about what is happening. I was hoping to offload that work to you and simply perform mechanical changes to the source! Rats! -- Robert Crocombe [EMAIL PROTECTED] - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
