----- Ursprüngliche Mail ----- > ----- Ursprüngliche Mail ----- >> Von: "Christian Loehle" <CLoehle@xxxxxxxxxxxxxx> >>> Can it be that rcar-gen3-sdhi changes some timings after switching? >>> Either in software or on hardware. >> >> Neither should be aware of the notion of a boot or user area partition. >> Anything below mmc/core isn't, if we exclude the boot operation which is read >> only, so not applicable to your problem. >> So also a >> while true; do dd if=/dev/zero of=/dev/mmcblkXboot0 bs=128K status=progress; >> done >> gives you like ~50KB/s consistently? > > Exactly. > > On the other hand, the very same command on /dev/mmcblk1p13 gives me always > between > 17 and 20 MB/s. I did further tracing and on Linux I see clearly that tmio_mmc_irq() always much later when writing to the boot area. Another idea, since u-boot does not really support interrupts it polls various status bits to detect completion of commands and data transfers. Crazy idea: Maybe u-boot writes are faster than they should because it polls not always the right bits? ...or Linux is too conservative and it matters for the boot area. Thanks, //richard
