| commit | d9ef5ce775b238646b16ac36ec09f0575fb1ac9f | |
| author | Alan Stern <stern@rowland.harvard.edu> | |
| Tue, 20 Jan 2009 20:33:26 +0000 (20 15:33 -0500) | ||
| committer | Greg Kroah-Hartman <gregkh@suse.de> | |
| Sun, 25 Jan 2009 00:41:41 +0000 (24 16:41 -0800) | ||
| tree | d7305d31ac7f722d2df489ce6e3ce53820b2ef05 | treesnapshot (tar.gz zip) |
| parent | 71bdefa43d7ae8622ff90bf6bed4ec963cdc1208 | commitdiff |
usb-storage: add last-sector hacks
commit 25ff1c316f6a763f1eefe7f8984b2d8c03888432 upstream.
This patch (as1189c) adds some hacks to usb-storage for dealing with
the growing problems involving bad capacity values and last-sector
accesses:
A new flag, US_FL_CAPACITY_OK, is created to indicate that
the device is known to report its capacity correctly. An
unusual_devs entry for Linux's own File-backed Storage Gadget
is added with this flag set, since g_file_storage always
reports the correct capacity and since the capacity need
not be even (it is determined by the size of the backing
file).
An entry in unusual_devs.h which has only the CAPACITY_OK
flag set shouldn't prejudice libusual, since the device will
work perfectly well with either usb-storage or ub. So a
new macro, COMPLIANT_DEV, is added to let libusual know
about these entries.
When a last-sector access fails three times in a row and
neither the FIX_CAPACITY nor the CAPACITY_OK flag is set,
we assume the last-sector bug is present. We replace the
existing status and sense data with values that will cause
the SCSI core to fail the access immediately rather than
retry indefinitely. This should fix the difficulties
people have been having with Nokia phones.
This version of the patch differs from the version accepted into the
mainline only in that it does not trigger a WARN() when an
odd-numbered last-sector access succeeds. In a stable kernel series
we don't want to go around spamming users' logs and consoles for no
good reason.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 25ff1c316f6a763f1eefe7f8984b2d8c03888432 upstream.
This patch (as1189c) adds some hacks to usb-storage for dealing with
the growing problems involving bad capacity values and last-sector
accesses:
A new flag, US_FL_CAPACITY_OK, is created to indicate that
the device is known to report its capacity correctly. An
unusual_devs entry for Linux's own File-backed Storage Gadget
is added with this flag set, since g_file_storage always
reports the correct capacity and since the capacity need
not be even (it is determined by the size of the backing
file).
An entry in unusual_devs.h which has only the CAPACITY_OK
flag set shouldn't prejudice libusual, since the device will
work perfectly well with either usb-storage or ub. So a
new macro, COMPLIANT_DEV, is added to let libusual know
about these entries.
When a last-sector access fails three times in a row and
neither the FIX_CAPACITY nor the CAPACITY_OK flag is set,
we assume the last-sector bug is present. We replace the
existing status and sense data with values that will cause
the SCSI core to fail the access immediately rather than
retry indefinitely. This should fix the difficulties
people have been having with Nokia phones.
This version of the patch differs from the version accepted into the
mainline only in that it does not trigger a WARN() when an
odd-numbered last-sector access succeeds. In a stable kernel series
we don't want to go around spamming users' logs and consoles for no
good reason.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>