Messages in this thread | | | Date | Sat, 11 Jun 2016 01:02:55 +0200 | From | Wim Osterholt <> | Subject | disfunctional floppy driver in kernels 4.5, 4.6 and 4.7 |
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L.S.
up to vanilla kernel 4.4.13 floppy functionality performs like it should. (On an x86 PC that is. With a 1.44MB diskette drive.) From kernel 4.5* and up it changed to barely usable.
After a virgin start (cold or warm boot) with an empty diskette drive and then loaded with a standard 720K diskette you may run 'mdir' (from mtools) and it shows the directory fine. The first time you load a standard 1.44MB diskette (wether it is a virgin start or after a 720K disktette) and you run mdir, it says literally:
plain_io: Input/output error init A: could not read boot sector Cannot initialize 'A:'
After this, all subsequent runs of mdir will do fine on both floppies. However, most of my floppies are in a different format. (1.6MB) I rely on 'setfdprm' (from fdutils) to set the correct parameters.
setfdprm /dev/fd0 1600/1440 /dev/fd0: Invalid argument
Strace shows me: ... open(/dev/fd0, O_ACCMODE) = -1
So this actually means that 'invalid argument' refers to O_ACCMODE.
At all kernels I see no changed rights in: ls -al /dev/fd0 brw-rw---- 1 root disk 2, 0 May 13 16:43 /dev/fd0
It looks to me that the code in floppy.c is quite old; no changes here. So the bug is elsewhere in the kernel.
Could someone please explain and repair the magic that is happening here?
Thanks in advance, Wim Osterholt.
----- wim@djo.tudelft.nl -----
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