lkml.org 
[lkml]   [2009]   [Apr]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] fsldma: use PCI Read Multiple command
    Hi Timur,

    >> Would you like some sort of summary of this info for a commit
    >> message?
    >
    > That's probably overkill. I just want a sentence or two that tells
    > someone looking at the code casually that the behavior of reading PCI
    > memory might be different than what they expect.

    Could you help us with the wording you'd like to see in the code.
    Did you want to see something in the header comments, or something
    near the register settings?

    How about something like this in place of the existing PCI_RM
    comment:

    PRC_RM - PCI read multiple
    The default PCI read command used by the DMA controller is
    PCI Read (PCI command 6h). When the burst length is 32-bytes
    or longer, PCI Read Line (PCI command Eh) is used (undocumented
    feature of the controller). Using PCI read multiple
    (PCI command Ch) results in high-performance across PCI
    bridges. DMA transfers to non-prefetchable PCI registers
    should not result in prefetched reads, even when using
    the PCI read multiple command.


    Cheers,
    Dave





    \
     
     \ /
      Last update: 2009-04-27 22:27    [W:0.021 / U:31.084 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site