Hi Ulf, On Thu, Nov 14, 2019 at 01:48:41PM +0100, Ulf Hansson wrote: [..] > > Let's first take a step back, because I don't know how the HW busy > detection works for your controller. > > I have noticed there is TMIO_STAT_CMD_BUSY bit being set for some > variants, which seems to cause renesas_sdhi_wait_idle() to loop for a > pre-defined number of loops/timeout. This looks scary, but I can't > tell if it's really a problem. > > BTW, do you know what TMIO_STAT_CMD_BUSY actually is monitoring? > > I have also noticed that MMC_CAP_WAIT_WHILE_BUSY isn't set for any of > the renesas/tmio variant hosts. Is that simply because the HW doesn't > support this? Or because implementation is missing? Hopefully Wolfram just addressed that? > If you want to run a test that stretches the behaviour on the timeout > path, I would rather use an SD-card (the older the better). For eMMCs > the erase likely translates to a trim/discard, which is far more > quicker than a real erase - as is what happens on an old SD card. Running 'blkdiscard' with different SD cards on H3ULCB, I don't see any signs of misbehavior: root@rcar-gen3:~# blkdiscard -V blkdiscard from util-linux 2.32.1 root@rcar-gen3:~# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT mmcblk0 179:0 0 59.2G 0 disk mmcblk0boot0 179:8 0 4M 1 disk mmcblk0boot1 179:16 0 4M 1 disk mmcblk1 179:24 0 30G 0 disk # Erasing 32 GiB uSD Card root@rcar-gen3:~# time blkdiscard -v /dev/mmcblk1 /dev/mmcblk1: Discarded 32227983360 bytes from the offset 0 real 0m1.198s user 0m0.001s sys 0m0.122s # Erasing 64 GiB eMMC root@rcar-gen3:~# time blkdiscard -v /dev/mmcblk0 /dev/mmcblk0: Discarded 63585648640 bytes from the offset 0 real 0m8.703s user 0m0.002s sys 0m1.909s I guess that by decreasing below erase sizes, I could further increase the execution time, but these sysfs properties are read-only: cat /sys/devices/platform/soc/ee100000.sd/mmc_host/mmc1/mmc1:59b4/preferred_erase_size 4194304 cat /sys/devices/platform/soc/ee100000.sd/mmc_host/mmc1/mmc1:59b4/erase_size 512 -- Best Regards, Eugeniu
