On Apr 4, 2013, at 13:12, "Fabio Estevam" <feste...@gmail.com> wrote:
> Hi Eric, > > On Wed, Apr 3, 2013 at 8:17 PM, Eric Nelson > <eric.nel...@boundarydevices.com> wrote: > >>> Actually, I'm a little confused by PRSSTAT_DLA checking: currently the >>> loop exits >>> when either IRQSTAT_TC occurs _or_ PRSSTAT_DLA flag comes to 0. Is that >>> correct? >>> I'm not quite familiar with using this flag, but should the loop exit when >>> both >>> IRQSTAT_TC occurs _and_ PRSSTAT_DLA flag comes to 0 (i.e. in current code >>> '&&' >>> should be replaced by '||')? And then the modified loop condition (with >>> DMA check) >>> would be >>> >>> } while (!(irqstat & IRQSTAT_TC) || !(irqstat & IRQSTAT_DINT) || >>> (esdhc_read32(®s->prsstat) & PRSSTAT_DLA)); >>> >>> Can you advise anything on using this flag? >> >> That is weird, and suspect. The reference manual indicates that this >> bit (Data line active) will go low when the data lines are done with >> the transaction, but that will happen before the DMA completes, so >> it seems like a bad way to short-circuit the loop. >> >> Fabio, can you comment on this? > > I am not very familiar with the mmc driver. Adding Andy in case he has > some insight about it. Hmm, that does seem weird. I'll look into it. > >> >> The code appears to have been like this since the beginning >> of main-line support for i.MX so there's no history to go on. >> >> The same goes in Freescale's git tree. > > Do you mean FSL U-boot or kernel tree? Is it the same with the > mainline kernel driver? > > Regards, > > Fabio Estevam > _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
