Arch Linux

Frefreak

Member

Registered: 2013-12-18

Posts: 25

SD/MMC device mount read-only.

My desktop has a builtin SD/mini/MMC/RS card slot and its fine until today. Every mmc/sd card becomes read-only after plugged in. I have tried with 2 SD cards and 1 eMMC card, all of them works fine in others' computers but not mine. I have googled this for a while and tried hdparm, dd, gparted, fdisk, fsck etc, all ends up with something like "cannot open, filesystem read-only".
dmesg outputs:

[Thu Nov 12 20:54:11 2015] sd 5:0:0:2: [sdd] 31116288 512-byte logical blocks: (15.9 GB/14.8 GiB)
[Thu Nov 12 20:54:11 2015] sd 5:0:0:2: [sdd] Write Protect is on
[Thu Nov 12 20:54:11 2015] sd 5:0:0:2: [sdd] Mode Sense: 03 00 80 00
[Thu Nov 12 20:54:11 2015]  sdd: sdd1
[Thu Nov 12 20:54:46 2015] sdd: detected capacity change from 15931539456 to 0
[Thu Nov 12 20:56:02 2015] sd 5:0:0:2: [sdd] 15523840 512-byte logical blocks: (7.94 GB/7.40 GiB)
[Thu Nov 12 20:56:02 2015]  sdd: sdd1

One of the cards I tried seems to have a hardware lock on it, but it's not the cause since it works fine on other computers (tested on Windows and Linux).
What could be the cause? Is the card reader slot's malfunction or software issue? If I remember correctly there's no problem even on yesterday. I'm using KDE 5, if this is related.

c0mm0ner

Member

Registered: 2015-11-09

Posts: 93

Re: SD/MMC device mount read-only.

To get it right: the error also occurs when you try something like "dd if=/dev/zero of=/dev/sdd"?

Frefreak

Member

Registered: 2013-12-18

Posts: 25

Re: SD/MMC device mount read-only.

To get it right: the error also occurs when you try something like "dd if=/dev/zero of=/dev/sdd"?

Yes, saying "cannot open Read/Write, read-only filesystem", or similar error.

I tried today with an external SD card reader (plugged in as USB), and everything's ok. Plugging in using built-in card reader slot is still read-only, more error message below:

[Fri Nov 13 08:49:51 2015] sd 5:0:0:2: [sdd] UNKNOWN(0x2003) Result: hostbyte=0x07 driverbyte=0x08
[Fri Nov 13 08:49:51 2015] sd 5:0:0:2: [sdd] Sense Key : 0x4 [current] 
[Fri Nov 13 08:49:51 2015] sd 5:0:0:2: [sdd] ASC=0x0 ASCQ=0x0 
[Fri Nov 13 08:49:51 2015] sd 5:0:0:2: [sdd] CDB: opcode=0x28 28 00 00 00 00 00 00 00 08 00
[Fri Nov 13 08:49:51 2015] blk_update_request: I/O error, dev sdd, sector 0
[Fri Nov 13 08:49:51 2015] Buffer I/O error on dev sdd, logical block 0, async page read
[Fri Nov 13 08:49:51 2015] ldm_validate_partition_table(): Disk read failed.

Does it mean the built-in slot has hardware problems?

Last edited by Frefreak (2015-11-13 00:58:26)

LCvanDinteren

Member

From: Netherlands

Registered: 2015-10-27

Posts: 153

Re: SD/MMC device mount read-only.

Perhaps a defect read-only switch? Most SD-cards have a small slider to "lock" the SD-card for writing.
Card readers detect this setting using a push-pin. If this push-pin is faulty, your reader could always think an SD-card has the read-only enabled.