very low frequency tech postings - hard/less_than_42in1.writeback
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Tue, 06 Feb 2007
less than 42 in 1you all know these flash-card readers which are being sold as 12-in-one readers or 23-in-one or even 42-in-one readers. I have one of these for a while now, which I had gotten from a flea market for 2 Euros. And for my new mobile phone I had gotten one of these tiny 2GB microSD cards.
The reader had worked fine with one of my old 32MB MMC cards, but not with the 2GB card. I was tempted to blame the linux kernel driver, but the investment of 20 Euros (what a fair price, I live in the jungle:) for a new reader proved it was a problem of the reader. Such a reader basically is a USB-based SPI-controller which translates host requests to SPI which the card understands. SPI itself has no addressing scheme, so the controller is to blame, having a limited address-space.
If you ever have trouble with a non-working flashcard, and find somthing like this in your logs:
kernel Initializing USB Mass Storage driver... kernel scsi0 : SCSI emulation for USB Mass Storage devices kernel usb-storage: device found at 3 kernel usb-storage: waiting for device to settle before scanning kernel usbcore: registered new interface driver usb-storage kernel USB Mass Storage support registered. kernel scsi 0:0:0:0: Direct-Access IC USB Storage-CFC 301b PQ: 0 ANSI: 0 CCS kernel scsi 0:0:0:1: Direct-Access IC USB Storage-SMC 301b PQ: 0 ANSI: 0 CCS kernel scsi 0:0:0:2: Direct-Access IC USB Storage-MMC 301b PQ: 0 ANSI: 0 CCS kernel scsi 0:0:0:3: Direct-Access IC USB Storage-MSC 301b PQ: 0 ANSI: 0 CCS kernel usb-storage: device scan complete kernel scsi.agent[20468]: disk at /devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2:1.0/host0/target0:0:0/0:0:0:2 kernel scsi.agent[20457]: disk at /devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2:1.0/host0/target0:0:0/0:0:0:3 kernel scsi.agent[20461]: disk at /devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2:1.0/host0/target0:0:0/0:0:0:1 kernel scsi.agent[20454]: disk at /devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2:1.0/host0/target0:0:0/0:0:0:0 kernel sd 0:0:0:0: Attached scsi removable disk sda kernel sd 0:0:0:1: Attached scsi removable disk sdb kernel sd 0:0:0:2: scsi: Device offlined - not ready after error recovery kernel sdc : READ CAPACITY failed. kernel sdc : status=0, message=00, host=1, driver=00 kernel sdc : sense not available. kernel sdc: Write Protect is off kernel sdc: Mode Sense: 00 00 00 00 kernel sdc: assuming drive cache: write through kernel sd 0:0:0:2: Attached scsi removable disk sdc kernel usb_id[20644]: usb_id: unable to access '/block/sda' kernel usb_id[20655]: usb_id: unable to access '/block/sdc' kernel usb_id[20684]: usb_id: unable to access '/block/sdb' kernel scsi_id[20685]: scsi_id: unable to access '/block/sdb' kernel scsi_id[20656]: scsi_id: unable to access '/block/sdc' kernel scsi_id[20739]: scsi_id: unable to access '/block/sdc' kernel scsi_id[20645]: scsi_id: unable to access '/block/sda' kernel scsi_id[20741]: scsi_id: unable to access '/block/sda' kernel scsi_id[20747]: scsi_id: unable to access '/block/sdb'get a new reader. If you want warranty forever, don't buy in germany (as I did, not reading the fine print ;). Italians: leave the country! Warranty for your great grantchildren's 22 ExaByte cards is to get elsewhere.
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