On Mon, 21 Oct 2019, Harald Dunkel wrote: > Hi Alan, > > On 10/19/19 4:57 PM, Alan Stern wrote: > > > > What happens if you don't use that rather slow 133x SD card? Do other > > cards work better? > > > > No problem with a 32 GByte SDHC card (U1). > > > Another possibility: If you attach the card adapter by a USB-2 cable > > then it will run as a USB-2 device (even when plugged into a USB-3 > > port). That probably would help -- although it would also slow down > > the data transfers. Although, come to think of it, slowing down the > > transfer rate may be just what this card needs... > > > > The USB2 cable worked, too. Actually I had expected that the speed is > reduced automatically according to the specs of the card. ??? That is doubtful. The speed of the connection is determined when the connection is first set up. Unless the reader disconnects itself from the USB bus when a card is removed and reconnects when a card is inserted, the speed can't change. You can see what the current connection speed is (in units of millions of bits per second) by looking in sysfs. For example: cat /sys/bus/usb/devices/2-10/speed (or maybe 2-5 instead of 2-10; both paths appeared in the kernel log you posted earlier). At any rate, it sounds like the 133x card is just too slow to keep up. Alan Stern
