Re: Detecting cards in USB card reader
On Sunday 07 February 2010, Nikos Vassiliadis wrote: While it may feel dangerous, is perfectly safe. There is no way doing an IO operation on a disk-like device using requests othen than multiplies of the physical block which currently is 512 bytes. Opening the disk for writing and trying to do a write request, will just force GEOM to re-examine the device. lab# echo asd | cat /dev/da0 cat: stdout: Invalid argument failed lab# echo /dev/da0 lab# echo $? 1 failed lab# /bin/echo asd /dev/da0 /bin/echo: write: Invalid argument failed Closer look: lab# truss sh -c echo /dev/da0 snip open(/dev/da0,O_WRONLY|O_CREAT|O_TRUNC,0666) = 2 (0x2) dup2(0x2,0x1,0x1b6,0x108,0x2830d040,0x2830235c) = 1 (0x1) close(2) = 0 (0x0) write(1,\n,1) ERR#22 'Invalid argument' failed FreeBSD lost the ability of doing such transparent transformations when the support for block devices went away. Yes, I know, it feels awkward. Apparently, you can easily drop the support for block devices but not the habitual feeling of danger of UNIX tradition. Thanks for the enlightening information. Although I didn't doubt that this was safe I couldn't help feeling that it seemed a wrong thing to do - a case of old habits being hard to loose. After seeing your explanation I feel much more confident about this. It does seem a pity though that we have to rely on the side effect of having no support for writing to block devices instead of having a specific means of detecting or checking for a media change in the card reader. -- Mike Clarke ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Detecting cards in USB card reader
On Wed, 10 Feb 2010, Mike Clarke wrote: It does seem a pity though that we have to rely on the side effect of having no support for writing to block devices instead of having a specific means of detecting or checking for a media change in the card reader. I agree that attempting a write to an unsuspecting device to signal a media change just looks wrong. usbconfig -d 3.3 reset seemed to work with my Sandisk card reader just now. This is still a side effect, but doesn't look as bad. -Warren Block * Rapid City, South Dakota USA ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Detecting cards in USB card reader
On 2/7/2010 1:28 AM, Mike Clarke wrote: curlew:/root# cat /dev/null /dev/da0 curlew:/root# ls -l /dev/da0* crw-r- 1 root operator0, 176 6 Feb 23:15 /dev/da0 crw-r- 1 root operator0, 129 6 Feb 23:18 /dev/da0s1 I can use this to initialise the card reader but I'd feel more comfortable with something a bit less dangerous looking. While it may feel dangerous, is perfectly safe. There is no way doing an IO operation on a disk-like device using requests othen than multiplies of the physical block which currently is 512 bytes. Opening the disk for writing and trying to do a write request, will just force GEOM to re-examine the device. lab# echo asd | cat /dev/da0 cat: stdout: Invalid argument failed lab# echo /dev/da0 lab# echo $? 1 failed lab# /bin/echo asd /dev/da0 /bin/echo: write: Invalid argument failed Closer look: lab# truss sh -c echo /dev/da0 snip open(/dev/da0,O_WRONLY|O_CREAT|O_TRUNC,0666) = 2 (0x2) dup2(0x2,0x1,0x1b6,0x108,0x2830d040,0x2830235c) = 1 (0x1) close(2) = 0 (0x0) write(1,\n,1) ERR#22 'Invalid argument' failed FreeBSD lost the ability of doing such transparent transformations when the support for block devices went away. Yes, I know, it feels awkward. Apparently, you can easily drop the support for block devices but not the habitual feeling of danger of UNIX tradition. HTH, Nikos ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Detecting cards in USB card reader
In an attempt to get round the problem that my Olympus C-2040Z camera won't communicate with FreeBSD versions above 6.4 I've installed an Akasa AK-ICR-01B internal card reader on my 8.0-RELEASE-p2 system. The reader is detected when the system boots and device nodes are created for da0, da1, da2 and da3. If a card is inserted before booting the computer it is detected and the appropriate device node is created (e.g. /dev/da0s1) but subsequently inserting a card into a slot which was empty fails to create the appropriate device. Playing around with camcontrol and restarting devd have no effect either. After a bit of Googling I found that 'cat /dev/null /dev/da0' appears to be the fix for forcing the creation of /dev/da0s1 after inserting a card in the slot associated with da0. Although this gets round the problem I can't help feeling uncomfortable about attempting to write to raw devices and was wondering if there was any suitable usbconfig or HAL incantation which could be used to achieve the desired effect in a safer looking way. -- Mike Clarke ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Detecting cards in USB card reader
On Sat, 6 Feb 2010 15:11:11 +, Mike Clarke jmc-freeb...@milibyte.co.uk wrote: Although this gets round the problem I can't help feeling uncomfortable about attempting to write to raw devices and was wondering if there was any suitable usbconfig or HAL incantation which could be used to achieve the desired effect in a safer looking way. I can understand this. Maybe accessing the SCSI layer of the card reader can help? If % camcontrol reset all will cause the same effect (of creating the correct nodes in /dev), you can be more precise (e. g. just reset da0); see % man camcontrol for further (and maybe more elegant) details. -- Polytropon Magdeburg, Germany Happy FreeBSD user since 4.0 Andra moi ennepe, Mousa, ... ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: Detecting cards in USB card reader
On Saturday 06 February 2010, Polytropon wrote: I can understand this. Maybe accessing the SCSI layer of the card reader can help? If % camcontrol reset all will cause the same effect (of creating the correct nodes in /dev), you can be more precise (e. g. just reset da0); see % man camcontrol for further (and maybe more elegant) details. Neither reset nor rescan have any effect with camcontrol. Without a suitable incantation like 'cat /dev/null /dev/da0' I just have /dev/da0 but no /dev/da0s1 after inserting a card. The system knows that the media is there, fdisk /dev/da0 can see the slice even, but there's no device node for it. This is what happens after inserting a 16MB card in the reader: curlew:/root# ls -l /dev/da0* crw-r- 1 root operator0, 176 6 Feb 23:15 /dev/da0 curlew:/root# fdisk /dev/da0 *** Working on device /dev/da0 *** parameters extracted from in-core disklabel are: cylinders=15 heads=64 sectors/track=32 (2048 blks/cyl) parameters to be used for BIOS calculations are: cylinders=15 heads=64 sectors/track=32 (2048 blks/cyl) Media sector size is 512 Warning: BIOS sector numbering starts with sector 1 Information from DOS bootblock is: The data for partition 1 is: sysid 1 (0x01),(Primary DOS with 12 bit FAT) start 32, size 31264 (15 Meg), flag 80 (active) beg: cyl 0/ head 1/ sector 1; end: cyl 488/ head 1/ sector 32 The data for partition 2 is: UNUSED The data for partition 3 is: UNUSED The data for partition 4 is: UNUSED curlew:/root# ls -l /dev/da0* crw-r- 1 root operator0, 176 6 Feb 23:15 /dev/da0 Still no device for slice 1 until after I attempt to open da0 for writing: curlew:/root# cat /dev/null /dev/da0 curlew:/root# ls -l /dev/da0* crw-r- 1 root operator0, 176 6 Feb 23:15 /dev/da0 crw-r- 1 root operator0, 129 6 Feb 23:18 /dev/da0s1 I can use this to initialise the card reader but I'd feel more comfortable with something a bit less dangerous looking. -- Mike Clarke ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
