Desktop computer, oS 13.2, KDE 4.14.6, Kernel 3.16.7-21-desktop x86_64
After inserting a cheap EMTEC USB3 16GB pendrive in a (obviously) USB3 port, KDE notifications takes approx. 60-65 seconds to show up with the removable device notice. Particulars:
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System load widget shows 1 core fully in I/O wait; iotop shows no process consuming large I/O, and the HDD led does not light up continuously, it just flashes now and then.
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The same delay happens when the pendrive is inserted in a USB2 port. Note: driver invoked in this case is xhci_hcd, not ehci.
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In W7 in the same computer there’s no delay, in either USB2 ou 3 port.
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In parted magic (a live distro with the XFCE desktop IINM), there’s no delay. The driver invoked is ehci-pci. Tested only in a USB2 port, no USB3 available in that machine.
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In an HP laptop running oS 13.1, KDE 4.11.5, Kernel 3.11.10-29-desktop x86_64 there is no delay. Driver is the same as the desktop, name-wise: xhci_hcd. Tested in a USB3 port.
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After the pendrive is recognized in oS, performance is similar to W7’s (i.e., better than USB2 but not that much, it’s a cheap device after all).
dmesg info when inserting pendrive in USB3 port of the desktop:
[73321.550748] usb 4-2: new SuperSpeed USB device number 2 using xhci_hcd
[73321.658227] usb 4-2: New USB device found, idVendor=6557, idProduct=5500
[73321.658229] usb 4-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[73321.658231] usb 4-2: Product: USB DISK 3.0
[73321.658232] usb 4-2: Manufacturer:
[73321.658233] usb 4-2: SerialNumber: 07014C96AAB2F989
[73321.658697] usb-storage 4-2:1.0: USB Mass Storage device detected
[73321.659195] scsi19 : usb-storage 4-2:1.0
[73322.715782] scsi 19:0:0:0: Direct-Access USB DISK 3.0 PMAP PQ: 0 ANSI: 6
[73322.715967] sd 19:0:0:0: Attached scsi generic sg8 type 0
[73323.702226] sd 19:0:0:0: [sdg] 30283008 512-byte logical blocks: (15.5 GB/14.4 GiB)
[73323.702331] sd 19:0:0:0: [sdg] Write Protect is off
[73323.702333] sd 19:0:0:0: [sdg] Mode Sense: 23 00 00 00
[73323.702447] sd 19:0:0:0: [sdg] No Caching mode page found
[73323.702449] sd 19:0:0:0: [sdg] Assuming drive cache: write through
[73323.728195] sdg: sdg1
[73323.729111] sd 19:0:0:0: [sdg] Attached SCSI removable disk
*----> this is where the delay happens <----*
[73384.701086] usb 4-2: reset SuperSpeed USB device number 2 using xhci_hcd
[73384.877063] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff8803ee282400
[73384.877066] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff8803ee282448
dmesg from HP laptop, also using USB3 port:
[48016.680729] usb 4-1: new SuperSpeed USB device number 2 using xhci_hcd
[48016.788981] usb 4-1: New USB device found, idVendor=6557, idProduct=5500
[48016.788987] usb 4-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[48016.788989] usb 4-1: Product: USB DISK 3.0
[48016.788991] usb 4-1: Manufacturer:
[48016.788993] usb 4-1: SerialNumber: 07014C96AAB2F989
[48016.801656] usb-storage 4-1:1.0: USB Mass Storage device detected
[48016.801800] scsi6 : usb-storage 4-1:1.0
[48016.802518] usbcore: registered new interface driver usb-storage
[48017.858208] scsi 6:0:0:0: Direct-Access USB DISK 3.0 PMAP PQ: 0 ANSI: 6
[48017.858837] sd 6:0:0:0: Attached scsi generic sg2 type 0
[48018.802517] sd 6:0:0:0: [sdc] 30283008 512-byte logical blocks: (15.5 GB/14.4 GiB)
[48018.803135] sd 6:0:0:0: [sdc] Write Protect is off
[48018.803146] sd 6:0:0:0: [sdc] Mode Sense: 23 00 00 00
[48018.803751] sd 6:0:0:0: [sdc] No Caching mode page found
[48018.803756] sd 6:0:0:0: [sdc] Assuming drive cache: write through
[48018.807993] sd 6:0:0:0: [sdc] No Caching mode page found
[48018.807999] sd 6:0:0:0: [sdc] Assuming drive cache: write through
[48018.831963] sdc: sdc1
[48018.834438] sd 6:0:0:0: [sdc] No Caching mode page found
[48018.834442] sd 6:0:0:0: [sdc] Assuming drive cache: write through
[48018.834446] sd 6:0:0:0: [sdc] Attached SCSI removable disk
I was close to lay the blame on the USB3 implementation on the cheap pendrive, but it works nicely on the laptop, so I don’t know how to fix this. Any ideas?
TIA