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. > > 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
