Commit Graph

181658 Commits

Author SHA1 Message Date
Tejun Heo 7d720c3e4f percpu: add __percpu sparse annotations to net
Add __percpu sparse annotations to net.

These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors.  This patch doesn't affect normal builds.

The macro and type tricks around snmp stats make things a bit
interesting.  DEFINE/DECLARE_SNMP_STAT() macros mark the target field
as __percpu and SNMP_UPD_PO_STATS() macro is updated accordingly.  All
snmp_mib_*() users which used to cast the argument to (void **) are
updated to cast it to (void __percpu **).

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Vlad Yasevich <vladislav.yasevich@hp.com>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 23:05:38 -08:00
David S. Miller 2bb4646fce Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-02-16 22:09:29 -08:00
jamal 6836b9bdd9 xfrm: avoid spinlock in get_acqseq() used by xfrm user
Eric's version fixed it for pfkey. This one is for xfrm user.
I thought about amortizing those two get_acqseq()s but it seems
reasonable to have two of these sequence spaces for the two different
interfaces.

cheers,
jamal
commit d5168d5addbc999c94aacda8f28a4a173756a72b
Author: Jamal Hadi Salim <hadi@cyberus.ca>
Date:   Tue Feb 16 06:51:22 2010 -0500

    xfrm: avoid spinlock in get_acqseq() used by xfrm user

    This is in the same spirit as commit 28aecb9d77
    by Eric Dumazet.
    Use atomic_inc_return() in get_acqseq() to avoid taking a spinlock

    Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 20:20:24 -08:00
Mike Frysinger e06d41d09f netdev: bfin_mac: drop experimental markings on RMII support
The code has been around for a long time now and is known to work on a
bunch of different parts/boards.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 20:20:23 -08:00
Linus Torvalds b0483e78e5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
  serial: 8250: add serial transmitter fully empty test
2010-02-16 16:56:21 -08:00
Linus Torvalds 18688218d1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6:
  USB: gadget: fix EEM gadget CRC usage
  USB: otg Kconfig: let USB_OTG_UTILS select USB_ULPI option
  USB: g_multi: fix CONFIG_USB_G_MULTI_RNDIS usage
  kfifo: Don't use integer as NULL pointer
  USB: FHCI: Fix build after kfifo rework
  kfifo: Make kfifo_initialized work after kfifo_free
  USB: serial: add usbid for dell wwan card to sierra.c
  USB: SIS USB2VGA DRIVER: support KAIREN's USB VGA adaptor USB20SVGA-MB-PLUS
  USB: ehci: phy low power mode bug fixing
  USB: s3c-hsotg: Export usb_gadget_register_driver()
  USB: r8a66597-udc: Prototype IS_ERR() and PTR_ERR()
  USB: ftdi_sio: add device IDs (several ELV, one Mindstorms NXT)
  USB: storage: Remove unneeded SC/PR from unusual_devs.h
  USB: ftdi_sio: new device id for papouch AD4USB
  USB: usbfs: properly clean up the as structure on error paths
  USB: usbfs: only copy the actual data received
2010-02-16 16:55:39 -08:00
Linus Torvalds 1ed10aa8e9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  class: Free the class private data in class_release
  sysfs: sysfs_sd_setattr set iattrs unconditionally
2010-02-16 16:55:13 -08:00
Linus Torvalds 5d67767047 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (22 commits)
  be2net: set proper value to version field in req hdr
  xfrm: Fix xfrm_state_clone leak
  ipcomp: Avoid duplicate calls to ipcomp_destroy
  ethtool: allow non-admin user to read GRO settings.
  ixgbe: fix WOL register setup for 82599
  ixgbe: Fix - Do not allow Rx FC on 82598 at 1G due to errata
  sfc: Fix SFE4002 initialisation
  mac80211: fix handling of null-rate control in rate_control_get_rate
  inet: Remove bogus IGMPv3 report handling
  iwlwifi: fix AMSDU Rx after paged Rx patch
  tcp: fix ICMP-RTO war
  via-velocity: Fix races on shared interrupts
  via-velocity: Take spinlock on set coalesce
  via-velocity: Remove unused IRQ status parameter from rx_srv and tx_srv
  rtl8187: Add new device ID
  iwmc3200wifi: Test of wrong pointer after kzalloc in iwm_mlme_update_bss_table()
  ath9k: Fix sequence numbers for PAE frames
  mac80211: fix deferred hardware scan requests
  iwlwifi: Fix to set correct ht configuration
  mac80211: Fix probe request filtering in IBSS mode
  ...
2010-02-16 16:52:04 -08:00
Jan Kiszka 771f4c87be CAPI: Remove experimental tag from middleware feature
Despite all its bugs, the middleware support of our CAPI stack was
already in use for many, many moons. And after going through its code,
fixing all issues I found, I feel it deserves to officially become a
non-experimental feature.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:36 -08:00
Jan Kiszka 79e95f4717 CAPI: Schedule capifs for removal
With dynamic TTY nodes and the help of udev, we no longer need this
special filesystem. Schedule it for removal in one year from now.

As a last duty to this feature, move its help to right option so that
users can read the rationale.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:36 -08:00
Jan Kiszka c6af043794 CAPI: Drop special controller lookup from capi20_put_message
This strange special rule to fall back to controller 1 cannot be derived
from the CAPI specs and looks a lot like it was once dedicated to some
out-of-tree driver, probably AVM's broken fcdsl2 (FRITZ!Card DSL v2.0).
I found no in-tree user that needs this check, and I'm now taking care
of the fcdsl2. So drop these bits from our stack.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:35 -08:00
Jan Kiszka eef0ced028 CAPI: Drop return value of handle_minor_send
We did not evaluate handle_minor_send's return value, just (void)'ed it
away. Time for a cleanup.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:35 -08:00
Jan Kiszka 2b72b5bd65 CAPI: Clean up capiminor_*_ack
No need for irqsave acquisition of acklock, bh-safe is sufficient.
Moverover, move kfree out of the lock and do not take acklock at all
in capiminor_del_all_ack as we are the last user of the list here.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:34 -08:00
Jan Kiszka dfbb84ffe9 CAPI: Fix locking around capiminor's output queue and drop workaround_lock
Introduce outlock as a spin lock that protects capiminor's outqueue,
outbytes and outskb (formerly known as ttyskb). outlock can be acquired
from soft-IRQ context via capinc_write, so make it bh-safe.

This finally removes the last reason for keeping the workaround lock
around (which was incomplete and partly broken anyway). And as we no
longer call handle_recv_skb in atomic context, gen_data_b3_resp_for can
use non-atomic allocation now.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:34 -08:00
Jan Kiszka 68d7347b28 CAPI: Drop capiminor's unused inbytes counter
The inbytes counter was only updated but never read.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:33 -08:00
Jan Kiszka 42792713f7 CAPI: Use atomics for capiminor's datahandle and msgid
The capiminor members datahandle and msgid are incremented outside any
lock, so better do this atomically.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:33 -08:00
Jan Kiszka 42651b5c1a CAPI: Rename datahandle_queue -> ackqueue_entry
This struct is describing a queue entry, not the queue itself.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:32 -08:00
Jan Kiszka a11ef7be8e CAPI: Rework capiminor RX handler
Avoid re-queuing skbs unless the error detected in handle_recv_skb is
expected to be recoverable such as lacking memory, a full CAPI queue, a
full TTY input buffer, or a not yet existing TTY.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:32 -08:00
Jan Kiszka b75b2eedcb CAPI: Drop handle_minor_recv from capinc_tty_write
Sending a message down the CAPI stack may trigger the reception of an
answer, but this will go through capi_recv_message and call
handle_minor_recv from there. There is no need to walk the receive queue
on capinc_tty_write.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:31 -08:00
Jan Kiszka a84fdf41b2 CAPI: Drop atomic ttyopencount
Not needed, tty->count keeps track of this information. At this chance,
drop traces of ancient attempts to debug this logic via _DEBUG_REFCOUNT.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:31 -08:00
Jan Kiszka 3d5d30fe7a CAPI: Clean up capiminors_lock
Use a plain spin lock for capiminors_lock, drop inconsistent irqsafe
acquisitions (it's only used in process context anyway).

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:30 -08:00
Jan Kiszka 6576c2891a CAPI: Drop obsolete nccip from capiminor struct
The nccip in capiminor used to serve as an indicator that the NCCI was
close. But we don't need this, we issue a hangup on capincci_free_minor.
So drop this legacy.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:30 -08:00
Jan Kiszka 30bced91d9 CAPI: Issue synchronous hangup on capincci_free_minor
capincci_free and, thus, capincci_free_minor runs in process context, so
we can issue the hangup of the associated TTY synchronously.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:29 -08:00
Jan Kiszka 2c8df72259 CAPI: Drop remaining NULL checks on tty->driver_data
tty_struct's driver_data cannot be NULL, no need to test for it.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:29 -08:00
Jan Kiszka fb4b4881ef CAPI: Use tty_port to keep track of capiminor's tty
Use the reference management features of tty_port to look up and drop
again the tty_struct associated with a capiminor.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:29 -08:00
Jan Kiszka 4632451180 CAPI: Establish install/cleanup handlers for capiminor TTYs
Properly associate/disassociate a capiminor object with its TTY via the
install/cleanup handlers instead of trying to guess first open and last
close.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:28 -08:00
Jan Kiszka 0159d5491f CAPI: Use kref on capiminor
Install a reference counter for capiminor objects. Acquire it when
obtaining a capiminor from the array during capinc_tty_open, drop it
when closing the tty again. Another reference is held for the hook-up
with capincci.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:28 -08:00
Jan Kiszka e95ac14386 CAPI: Use dynamic major for NCCI TTYs by default
No need to allocate a fixed major for this TTY, both capifs and udev
make this transparent to the user.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:27 -08:00
Jan Kiszka 40fb2d0da7 CAPI: Dynamically register minor devices
Register capiminors dynamically with the TTY core so that udev can make
them show up as the NCCIs appear or disappear. This removes the need to
check if the capiminor requested in capinc_tty_open actually exists.

And this completely obsoletes capifs which will be scheduled for removal
in a later patch.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:27 -08:00
Jan Kiszka e76b154407 CAPI: Clean up capinc_tty_init/exit
Return proper error code if tty_register_driver fails. In contrast,
tty_unregister_driver cannot practically fail, so drop that error
handling. Finally, mark capinc_tty_init/exit with __init/__exit.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:26 -08:00
Jan Kiszka 81d17fe5e2 CAPI: Switch capiminor list to array
Using a plain array of pointers simplifies the management of capiminors.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:26 -08:00
Jan Kiszka 884f5c4479 CAPI: Switch NCCI list to standard doubly linked list
Replace open-coded NCCI list management with standard mechanisms.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:25 -08:00
Jan Kiszka 28a1dbb6f7 CAPI: Fix racy capi_read
capi_read still used interruptible_sleep_on, risking to miss a wakeup
this way. Convert it to wait_event_interruptible.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:25 -08:00
Jan Kiszka 54f0fad3d8 CAPI: Use non-atomic allocation during NCCI setup
Both capincci_alloc and capiminor_alloc run in non-atomic context,
update their memory allocations accordingly.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:24 -08:00
Jan Kiszka 05b4149433 CAPI: Rework locking of capidev members
Rename 'ncci_list_mtx' to 'lock', expressing that it now protects a
larger set of capidev members: the NCCI list, ap.applid (ie. the
registration of the application), and modifications of userflags.

We do not need to protect each and every check for ap.applid because,
once an application is registered, it will stay for the whole lifetime
of the device.

Also, there is no need to apply the capidev mutex during release (if
there could be concurrent users, we would crash them anyway by freeing
the device at the end of capi_release).

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:24 -08:00
Jan Kiszka eca39dd830 CAPI: Clean up capi_open/release
Fold capidev_alloc and capidev_free into capi_open and capi_release -
there are no other users. Someone pushed a lock_kernel into capi_open.
Drop it, we don't need it. Also remove the useless test from open that
checks for private_data == NULL.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:23 -08:00
Jan Kiszka b8f433dc5c CAPI: Convert capidev_list_lock into a mutex
No need for anything "harder" here (specifically no need for
irqsave...). Also, make the list removal the first operation of
capidev_free to avoid dumping half-released devices via /proc.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:23 -08:00
Jan Kiszka 501c87a919 CAPI: Reduce #ifdef mess around CONFIG_ISDN_CAPI_MIDDLEWARE
Make the code a bit more readable be providing stub functions for the
!CONFIG_ISDN_CAPI_MIDDLEWARE case. Though a few lines are moved around,
this comes with no functional changes.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:23 -08:00
Jan Kiszka 88c896ef87 CAPI: Rework application locking
Drop the application rw-lock in favour of RCU. This synchronizes
capi20_release against capi_ctr_handle_message which may dereference an
application from (soft-)IRQ context. Any other access to the application
list is now protected by the capi_controller_lock as well. This also
allows to safely inspect applications for /proc dumping by holding
capi_controller_lock.

At this chance, drop some useless release_in_progress checks where we
obtained the application pointer from the list (which becomes NULL on
release_in_progress).

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:22 -08:00
Jan Kiszka 0ca3a017a7 CAPI: Rework locking of controller data structures
This patch applies the mutex so far only protecting the controller list
to (almost) all accesses of controller data structures. It also reworks
waiting on state changes in old_capi_manufacturer so that it no longer
poll and holds a module reference to the controller owner while waiting
(the latter was partly done already). Modification and checking of the
blocked state remains racy by design, the caller is responsible for
dealing with this.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:22 -08:00
Jan Kiszka ef69bb2ec6 CAPI: Rework controller state notifier
Another step towards proper locking: Rework the callback provided to
capidrv for controller state changes. This is so far attached to an
application, which would require us to hold the corresponding lock
across notification calls.

But there is no direct relation between a controller up/down event and
an application, so let's decouple them and provide a notifier call chain
for those events instead. This notifier chain is first of all used
internally. Here we request the highest priority to unsure that
housekeeping work is done before any other notifications. The chain is
exported via [un]register_capictr_notifier to our only user, capidrv, to
replace the racy and unfixable capi20_set_callback.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:21 -08:00
Jan Kiszka 3efecf7a49 CAPI: Rework capi_ctr_ready/down
This step prepares the application of proper controller locking: Push
all state changing work into the notify handler that are called by
capi_ctr_ready and capi_ctr_down, switch detach_capi_ctr to issue a
synchronous ctr_down. Also ensure that we do not go through any action
if the state did not change.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:21 -08:00
Jan Kiszka 9717fb8b64 CAPI: Convert capi drivers rwlock into mutex
Turn the lock protecting registered capi drivers into a mutex and apply
it consistently.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:20 -08:00
Jan Kiszka 522530311b CAPI: Call a controller 'controller', not 'card'
At least for our internal use, fix the misnomers that refer to a CAPI
controller as 'card'. No functional changes.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:20 -08:00
Jan Kiszka 88549d6b76 CAPI: Reduce chattiness during module loading/removal
The CVS revisions dumped by all CAPI modules are meaningless today. And
that some CAPI module is loaded or removed does not necessarily deserve
a message. Just keep the message of the central module, capi.ko, drop
the rest.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:19 -08:00
Jan Kiszka e11e7ac1ec CAPI: Pin capifs instead of mounting it
Auto-mounting the capifs during module init prevents unloading its
module. Instead, pin the filesystem as long as some NCCI node exists.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:19 -08:00
Jan Kiszka 07ad603ab8 CAPI: Eliminate capifs_root variable
capifs_mnt->mnt_sb->s_root already contains what we need.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:18 -08:00
Jan Kiszka 90926f0e58 CAPI: Sanitize capifs API
Instead of looking up the dentry of an NCCI node again in
capifs_free_ncci pass the pointer via the capifs user.

This patch also reduces the #ifdef mess in capi.c a bit as far as capifs
was causing it.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:18 -08:00
Jan Kiszka c947862f91 CAPI: Fix leaks in capifs_new_ncci
When something went wrong during capifs_new_ncci, the looked up dentry
was not properly released. Neither was the allocated inode. Refactor the
function to avoid leaks.

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16 16:01:17 -08:00
Dick Hollenbeck bca476139d serial: 8250: add serial transmitter fully empty test
When controlling an industrial radio modem it can be necessary to
manipulate the handshake lines in order to control the radio modem's
transmitter, from userspace.

The transmitter should not be turned off before all characters have been
transmitted.  serial8250_tx_empty() was reporting that all characters were
transmitted before they actually were.

===

Discovered in parallel with more testing and analysis by Kees Schoenmakers
as follows:

I ran into an NetMos 9835 serial pci board which behaves a little
different than the standard.  This type of expansion board is very common.

"Standard" 8250 compatible devices clear the 'UART_LST_TEMT" bit together
with the "UART_LSR_THRE" bit when writing data to the device.

The NetMos device does it slightly different

I believe that the TEMT bit is coupled to the shift register.  The problem
is that after writing data to the device and very quickly after that one
does call serial8250_tx_empty, it returns the wrong information.

My patch makes the test more robust (and solves the problem) and it does
not affect the already correct devices.

Alan:

  We may yet need to quirk this but now we know which chips we have a
  way to do that should we find this breaks some other 8250 clone with
  dodgy THRE.

Signed-off-by: Dick Hollenbeck <dick@softplc.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Kees Schoenmakers <k.schoenmakers@sigmae.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-02-16 15:55:51 -08:00