Messages in this thread | | | Date | Wed, 19 Dec 2007 15:49:32 +0800 | From | "Dave Young" <> | Subject | Re: 2.6.24-rc5-mm1 |
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On Dec 17, 2007 9:14 AM, Dave Young <hidave.darkstar@gmail.com> wrote: > On Dec 14, 2007 11:44 PM, Alan Stern <stern@rowland.harvard.edu> wrote: > > On Fri, 14 Dec 2007, Dave Young wrote: > > > > > Hi, > > > The behaviour of my mp3 player (also act as usb-storage device) seems > > > changed from rc5 to rc5-mm1. > > > > This can't be considered a bug, right? > > I'm not sure. > > > > It's just that the player > > changed from one slightly non-standard behavior to a different slightly > > non-standard behavior. > > > > > > > <dmesg output under rc5>: > > > ========= > > > usb 1-7: new high speed USB device using ehci_hcd and address 7 > > > usb 1-7: configuration #1 chosen from 1 choice > > > scsi4 : SCSI emulation for USB Mass Storage devices > > > usb-storage: device found at 7 > > > usb-storage: waiting for device to settle before scanning > > > scsi 4:0:0:0: Direct-Access Newman mp3 PQ: 0 ANSI: 0 CCS > > > sd 4:0:0:0: [sdb] 245248 512-byte hardware sectors (126 MB) > > > sd 4:0:0:0: [sdb] Write Protect is on > > > sd 4:0:0:0: [sdb] Mode Sense: 03 00 80 00 > > > sd 4:0:0:0: [sdb] Assuming drive cache: write through > > > sd 4:0:0:0: [sdb] 245248 512-byte hardware sectors (126 MB) > > > sd 4:0:0:0: [sdb] Write Protect is on > > > sd 4:0:0:0: [sdb] Mode Sense: 03 00 80 00 > > > sd 4:0:0:0: [sdb] Assuming drive cache: write through > > > sdb: sdb1 > > > sd 4:0:0:0: [sdb] Attached SCSI removable disk > > > sd 4:0:0:0: Attached scsi generic sg1 type 0 > > > usb-storage: device scan complete > > > > > > ========== > > > try mount it (or just blockdev --rereadpt), then write protect become off: > > > ========== > > > > > > sd 4:0:0:0: [sdb] 245248 512-byte hardware sectors (126 MB) > > > sd 4:0:0:0: [sdb] Write Protect is off > > > sd 4:0:0:0: [sdb] Mode Sense: 03 00 00 00 > > > sd 4:0:0:0: [sdb] Assuming drive cache: write through > > > sd 4:0:0:0: [sdb] 245248 512-byte hardware sectors (126 MB) > > > sd 4:0:0:0: [sdb] Write Protect is off > > > sd 4:0:0:0: [sdb] Mode Sense: 03 00 00 00 > > > sd 4:0:0:0: [sdb] Assuming drive cache: write through > > > sdb: sdb1 > > > > This output won't appear if you simply mount the device. So how do you > > know that mounting turns off write protect? > > This can be observed by eye: > dmesg -> mount -> dmesg > > > > > > But under rc5-mm1, after mount command being executed, it is just > > > mouted as read only partition without set the write-protect to off > > > > > > I tried "blockdev --rereadpt", it do set the write-protect to off as rc5 kernel. > > > > > > Below is the output of dmesg under rc5-mm1 > > > ========== > > > usb 1-8: new high speed USB device using ehci_hcd and address 6 > > > usb 1-8: configuration #1 chosen from 1 choice > > > scsi3 : SCSI emulation for USB Mass Storage devices > > > usb-storage: device found at 6 > > > usb-storage: waiting for device to settle before scanning > > > scsi 3:0:0:0: Direct-Access Newman mp3 PQ: 0 ANSI: 0 CCS > > > sd 3:0:0:0: [sdb] 245248 512-byte hardware sectors (126 MB) > > > sd 3:0:0:0: [sdb] Write Protect is on > > > sd 3:0:0:0: [sdb] Mode Sense: 03 00 80 00 > > > sd 3:0:0:0: [sdb] Assuming drive cache: write through > > > sd 3:0:0:0: [sdb] 245248 512-byte hardware sectors (126 MB) > > > sd 3:0:0:0: [sdb] Write Protect is on > > > sd 3:0:0:0: [sdb] Mode Sense: 03 00 80 00 > > > sd 3:0:0:0: [sdb] Assuming drive cache: write through > > > sdb: sdb1 > > > > This looks exactly the same as the output above (except for various > > port, device, and bus numbers). > > Yes, but lacks the part of "'Write Protect if off' and other lines". > > > > > If you turn on CONFIG_USB_STORAGE_DEBUG for both kernels and compare > > the dmesg output for the mount command, that might highlight the > > difference. > > Ok, I will test with do once have time, thanks. >
There's not useful infomation with DEBUG on.
I tested on another machine with kernel 2.6.24-rc2. And the result is diffrent again. Here is the result:
1. on 2.6.24-rc2, when I plugin the player the kernel reports below messages:
usb-storage: waiting for device to settle before scanning /*[lets mark the below part as part 1]*/ scsi 0:0:0:0: Direct-Access Newman mp3 PQ: 0 ANSI: 0 CCS sd 0:0:0:0: [sda] 245248 512-byte hardware sectors (126 MB) sd 0:0:0:0: [sda] Write Protect is on sd 0:0:0:0: [sda] Mode Sense: 03 00 80 00 sd 0:0:0:0: [sda] Assuming drive cache: write through sd 0:0:0:0: [sda] 245248 512-byte hardware sectors (126 MB) sd 0:0:0:0: [sda] Write Protect is on sd 0:0:0:0: [sda] Mode Sense: 03 00 80 00 sd 0:0:0:0: [sda] Assuming drive cache: write through sda: sda1 /*[lets mark the below part as part 2]*/ sd 0:0:0:0: [sda] Attached SCSI removable disk usb-storage: device scan complete sd 0:0:0:0: [sda] 245248 512-byte hardware sectors (126 MB) sd 0:0:0:0: [sda] Write Protect is off sd 0:0:0:0: [sda] Mode Sense: 03 00 00 00 sd 0:0:0:0: [sda] Assuming drive cache: write through sd 0:0:0:0: [sda] 245248 512-byte hardware sectors (126 MB) sd 0:0:0:0: [sda] Write Protect is off sd 0:0:0:0: [sda] Mode Sense: 03 00 00 00 sd 0:0:0:0: [sda] Assuming drive cache: write through sda: sda1
2. on 2.6.24-rc5 kernel reports only the part 1, after try mount the disk it reports the part 2 and mount the partition as rw
3. on 2.6.24-rc5 kernel reports only the part 1, after try mount the disk it just mount the partition as ro with nothing more messages.
Regards dave
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