当我将 SD 卡插入 SD 卡插槽时，操作系统检测到已插入磁盘，但未列出分区，因此我无法安装卡来访问分区。我必须多次插入 SD 卡才能检测到分区。
我测试过的所有 SD 卡（至少 10 种不同的卡）和不同的 SD 适配器都会发生这种情况。
当我将 SD 卡插入插槽且未找到分区时，这是 dmesg 的输出：
[719887.160646] usb 1-4: new high-speed USB device number 121 using xhci_hcd
[719887.310469] usb 1-4: New USB device found, idVendor=058f, idProduct=6366
[719887.310472] usb 1-4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[719887.310473] usb 1-4: Product: Flash Card Reader/Writer
[719887.310475] usb 1-4: Manufacturer: Generic
[719887.310476] usb 1-4: SerialNumber: 058F63666485
[719887.311379] usb-storage 1-4:1.0: USB Mass Storage device detected
[719887.311506] scsi host4: usb-storage 1-4:1.0
[719888.329456] scsi 4:0:0:0: Direct-Access Multiple Card Reader 1.00 PQ: 0 ANSI: 4
[719888.329714] sd 4:0:0:0: Attached scsi generic sg2 type 0
当找到分区时：
[720057.687773] usb 1-4: new high-speed USB device number 122 using xhci_hcd
[720057.837576] usb 1-4: New USB device found, idVendor=058f, idProduct=6366
[720057.837578] usb 1-4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[720057.837579] usb 1-4: Product: Flash Card Reader/Writer
[720057.837581] usb 1-4: Manufacturer: Generic
[720057.837582] usb 1-4: SerialNumber: 058F63666485
[720057.838184] usb-storage 1-4:1.0: USB Mass Storage device detected
[720057.838295] scsi host4: usb-storage 1-4:1.0
[720058.848648] scsi 4:0:0:0: Direct-Access Multiple Card Reader 1.00 PQ: 0 ANSI: 4
[720058.848919] sd 4:0:0:0: Attached scsi generic sg2 type 0
[720059.385156] sd 4:0:0:0: [sdc] 60637184 512-byte logical blocks: (31.0 GB/28.9 GiB)
[720059.387009] sd 4:0:0:0: [sdc] Write Protect is on
[720059.387011] sd 4:0:0:0: [sdc] Mode Sense: 23 00 80 00
[720059.388888] sd 4:0:0:0: [sdc] Write cache: disabled, read cache: disabled, doesn't support DPO or FUA
[720059.395318] sdc: sdc1
[720059.400132] sd 4:0:0:0: [sdc] Attached SCSI removable disk
为什么分区无法被识别？如何才能让 SD 卡上的分区立即被识别？
我正在使用 Ubuntu 16.04 LTS
更新：
我尝试使用 FCR-MRR 和通用 USB 读卡器读取 SD 卡。我得到了不同的结果：
FCR-MRR，我可以看到 /dev/sdc，但没有分区：
[781195.153227] usb 1-1: new high-speed USB device number 37 using xhci_hcd
[781195.308811] usb 1-1: New USB device found, idVendor=090c, idProduct=6200
[781195.308814] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[781195.308815] usb 1-1: Product: Generic USB2.0 card
[781195.308817] usb 1-1: Manufacturer: Silicon Motion, Inc.
[781195.308818] usb 1-1: SerialNumber: 12345678901234567890
[781195.309589] usb-storage 1-1:1.0: USB Mass Storage device detected
[781195.309686] scsi host5: usb-storage 1-1:1.0
[781196.333858] scsi 5:0:0:0: Direct-Access Generic USB SD Reader 1.00 PQ: 0 ANSI: 0 CCS
[781196.334282] sd 5:0:0:0: Attached scsi generic sg3 type 0
[781196.334941] sd 5:0:0:0: [sdd] Attached SCSI removable disk
通用 USB 读卡器，未列出 /dev/sdc：
[781244.211748] usb 1-1: new high-speed USB device number 38 using xhci_hcd
[781244.361940] usb 1-1: New USB device found, idVendor=14cd, idProduct=1212
[781244.361942] usb 1-1: New USB device strings: Mfr=1, Product=3, SerialNumber=2
[781244.361944] usb 1-1: Product: Mass Storage Device
[781244.361945] usb 1-1: Manufacturer: Generic
[781244.361946] usb 1-1: SerialNumber: 121220160204
[781244.362718] usb-storage 1-1:1.0: USB Mass Storage device detected
[781244.362815] scsi host5: usb-storage 1-1:1.0
[781245.375268] scsi 5:0:0:0: Direct-Access Mass Storage Device 1.00 PQ: 0 ANSI: 0 CCS
[781245.375485] sd 5:0:0:0: Attached scsi generic sg3 type 0
我也在另一台装有 Debian 的 PC 上尝试过，结果相同。但是，如果我使用 spektra mini 读卡器，我可以毫无问题地读取我的所有 SD 卡。