- 16 1月, 2013 3 次提交
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由 Jiri Slaby 提交于
One point is to have less places where we actually need tty pointer. The other is that low_latency is bound to buffer processing and buffers are now in tty_port. So it makes sense to move low_latency to tty_port too. Signed-off-by: NJiri Slaby <jslaby@suse.cz> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Jiri Slaby 提交于
Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty in many call sites. Only tty_port will needed and hence no more tty_port_tty_get in those paths. tty_insert_flip_string this time. Signed-off-by: NJiri Slaby <jslaby@suse.cz> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Jiri Slaby 提交于
Now, we start converting tty buffer functions to actually use tty_port. This will allow us to get rid of the need of tty in many call sites. Only tty_port will needed and hence no more tty_port_tty_get in those paths. tty_insert_flip_char is the next one to proceed. This one is used all over the code, so the patch is huge. Signed-off-by: NJiri Slaby <jslaby@suse.cz> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 16 11月, 2012 1 次提交
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由 Jiri Slaby 提交于
After commit "TTY: move tty buffers to tty_port", the tty buffers are not freed in some drivers. This is because tty_port_destructor is not called whenever a tty_port is freed. This was an assumption I counted with but was unfortunately untrue. So fix the drivers to fulfil this assumption. To be sure, the TTY buffers (and later some stuff) are gone along with the tty_port, we have to call tty_port_destroy at tear-down places. This is mostly where the structure containing a tty_port is freed. This patch does exactly that -- put tty_port_destroy at those places. Signed-off-by: NJiri Slaby <jslaby@suse.cz> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 15 11月, 2012 1 次提交
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由 Heiko Carstens 提交于
The 3215 console always has the RAW3215_FIXED flag set, which causes raw3215_shutdown() not to wait for outstanding I/O requests if an attached tty gets closed. The flag however can be simply removed, so we can guarantee that all requests belonging to the tty have been processed when the tty is closed. However the tasklet that belongs to the 3215 device may be scheduled even if there is no tty attached anymore, since we have a race between console and tty processing. Thefore unconditional tty_wakekup() in raw3215_wakeup() can cause the following NULL pointer dereference: 3.465368 Unable to handle kernel pointer dereference at virtual kernel address (null) 3.465448 Oops: 0004 #1 SMP 3.465454 Modules linked in: 3.465459 CPU: 1 Not tainted 3.6.0 #1 3.465462 Process swapper/1 (pid: 0, task: 000000003ffa4428, ksp: 000000003ffb7ce0) 3.465466 Krnl PSW : 0404100180000000 0000000000162f86 (__wake_up+0x46/0xb8) 3.465480 R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:0 CC:1 PM:0 EA:3 Krnl GPRS: fffffffffffffffe 0000000000000000 0000000000000160 0000000000000001 3.465492 0000000000000001 0000000000000004 0000000000000004 000000000096b490 3.465499 0000000000000001 0000000000000100 0000000000000001 0000000000000001 3.465506 070000003fc87d60 0000000000000160 000000003fc87d68 000000003fc87d00 3.465526 Krnl Code: 0000000000162f76: e3c0f0a80004 lg %r12,168(%r15) 0000000000162f7c: 58000370 l %r0,880 #0000000000162f80: c007ffffffff00 xilf %r0,4294967295 >0000000000162f86: ba102000 cs %r1,%r0,0(%r2) 0000000000162f8a: 1211 ltr %r1,%r1 0000000000162f8c: a774002f brc 7,162fea 0000000000162f90: b904002d lgr %r2,%r13 0000000000162f94: b904003a lgr %r3,%r10 3.465597 Call Trace: 3.465599 (<0400000000000000> 0x400000000000000) 3.465602 <000000000048c77e> raw3215_wakeup+0x2e/0x40 3.465607 <0000000000134d66> tasklet_action+0x96/0x168 3.465612 <000000000013423c> __do_softirq+0xd8/0x21c 3.465615 <0000000000134678> irq_exit+0xa8/0xac 3.465617 <000000000046c232> do_IRQ+0x182/0x248 3.465621 <00000000005c8296> io_return+0x0/0x8 3.465625 <00000000005c7cac> vtime_stop_cpu+0x4c/0xb8 3.465629 (<0000000000194e06> tick_nohz_idle_enter+0x4e/0x74) 3.465633 <0000000000104760> cpu_idle+0x170/0x184 3.465636 <00000000005b5182> smp_start_secondary+0xd6/0xe0 3.465641 <00000000005c86be> restart_int_handler+0x56/0x6c 3.465643 <0000000000000000> 0x0 3.465645 Last Breaking-Event-Address: 3.465647 <0000000000403136> tty_wakeup+0x46/0x98 3.465652 3.465654 Kernel panic - not syncing: Fatal exception in interrupt 01: HCPGIR450W CP entered; disabled wait PSW 00020001 80000000 00000000 0010F63C The easiest solution is simply to check if tty is NULL in the tasklet. If it is NULL nothing is to do (no tty attached), otherwise tty_wakeup() can be called, since we hold a reference to the tty. This is not nice... but it is a small patch and it works. Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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- 14 8月, 2012 2 次提交
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由 Jiri Slaby 提交于
This has two outcomes: * we give the TTY layer a tty_port * we do not find the info structure every time open is called on that tty Signed-off-by: NJiri Slaby <jslaby@suse.cz> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: linux-s390@vger.kernel.org Acked-by: NAlan Cox <alan@linux.intel.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Jiri Slaby 提交于
raw3215[line] is set in probe, but not unset in remove. This will lead to random crashes if the device is removed and the corresponding tty opened later. open would dereference freed memory. So set raw3215[line] to NULL in remove to fix that. Signed-off-by: NJiri Slaby <jslaby@suse.cz> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: linux-s390@vger.kernel.org Acked-by: NAlan Cox <alan@linux.intel.com> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 18 4月, 2012 1 次提交
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由 Heiko Carstens 提交于
Fix compile error caused by "TTY: con3215, use tty from tty_port": CC drivers/s390/char/con3215.o drivers/s390/char/con3215.c: In function 'raw3215_wakeup': drivers/s390/char/con3215.c:339:16: error: 'struct raw3215_info' has no member named 'tty' make[1]: *** [drivers/s390/char/con3215.o] Error 1 make: *** [drivers/s390/char/] Error 2 Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Acked-by: NJiri Slaby <jslaby@suse.cz> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 14 4月, 2012 2 次提交
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由 Jiri Slaby 提交于
Obtain tty_struct only once in ISR and pass it down to raw3215_next_io. Other than that, we just use the tty with raised reference. And set it properly in open and close. Signed-off-by: NJiri Slaby <jslaby@suse.cz> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: linux-s390@vger.kernel.org Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Jiri Slaby 提交于
And use flags from that. But first we have to get rid of duplicated flag names. From now on, for the standard ones that are stored in tty_port->flags, we use ASYNC_* ones. Signed-off-by: NJiri Slaby <jslaby@suse.cz> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: linux-s390@vger.kernel.org Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 10 4月, 2012 1 次提交
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由 Jiri Slaby 提交于
There are two copies of allocations of device information. One of them is totally broken. See: raw->cdev = cdev; raw->inbuf = (char *) raw + sizeof(struct raw3215_info); memset(raw, 0, sizeof(struct raw3215_info)); It suggests that this path was never executed. The code uses both raw->cdev and raw->inbuf all over. And it is NULL due to the memset here, so it would panic immediately. I believe nobody used that driver without being a system console. Either way, let us fix it by moving the allocations (and initializations) to a single place. This will save us some double initializations later too. And while at it, initialize the timer properly -- once, at the allocation. Signed-off-by: NJiri Slaby <jslaby@suse.cz> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: linux-s390@vger.kernel.org Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 09 3月, 2012 2 次提交
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由 Jiri Slaby 提交于
Checking if tty->index is in bounds is not needed. The tty has the index set in the initial open. This is done in get_tty_driver. And it can be only in interval <0,driver->num). So remove the tests which check exactly this interval. Some are left untouched as they check against the current backing device count. (Leaving apart that the check is racy in most of the cases.) Signed-off-by: NJiri Slaby <jslaby@suse.cz> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Jiri Slaby 提交于
All num, magic and owner are set by alloc_tty_driver. No need to re-set them on each allocation site. pti driver sets something different to what it passes to alloc_tty_driver. It is not a bug, since we don't use the lines parameter in any way. Anyway this is fixed, and now we do the right thing. Signed-off-by: NJiri Slaby <jslaby@suse.cz> Acked-by: NTilman Schmidt <tilman@imap.cc> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 17 2月, 2012 1 次提交
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由 Martin Schwidefsky 提交于
The 3215 driver calls tty_wakeup from irq context while holding the device spinlock. If printk is called by any function on the callchain starting from tty_wakeup the system deadlocks on the device spinlock. Using a tasklet to call tty_wakup solves the problem. Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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- 30 10月, 2011 1 次提交
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由 Peter Oberparleiter 提交于
Current IRQ statistics support does not show detail counts for I/O interrupts which are processed internally only. The result is a summation count which is way off such as this one: CPU0 CPU1 CPU2 I/O: 1331 710 442 [...] QAI: 15 16 16 [I/O] QDIO Adapter Interrupt QDI: 1 0 0 [I/O] QDIO Interrupt DAS: 706 645 381 [I/O] DASD C15: 26 10 0 [I/O] 3215 C70: 0 0 0 [I/O] 3270 TAP: 0 0 0 [I/O] Tape VMR: 0 0 0 [I/O] Unit Record Devices LCS: 0 0 0 [I/O] LCS CLW: 0 0 0 [I/O] CLAW CTC: 0 0 0 [I/O] CTC APB: 0 0 0 [I/O] AP Bus Fix this by moving I/O interrupt accounting into the common I/O layer. Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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- 23 3月, 2011 1 次提交
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由 Sebastian Ott 提交于
Remove the owner and name members of struct ccw_driver and convert all drivers to store this data in the embedded struct device_driver. Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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- 05 1月, 2011 1 次提交
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由 Heiko Carstens 提交于
Add support for 3215 I/O interrupt statistics in /proc/interrupts. Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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- 14 1月, 2010 1 次提交
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由 Heiko Carstens 提交于
...instead of adding a compat ioctl function which would do nothing as well. Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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- 07 12月, 2009 1 次提交
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由 Heiko Carstens 提交于
When converting these two drivers from bootmem to slab allocations I forgot to remove two comments which state that this wouldn't be possible. So remove them now since this caused confusion already. Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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- 22 6月, 2009 2 次提交
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由 Martin Schwidefsky 提交于
Replace the remaining direct accesses to the driver_data pointer with calls to the dev_get_drvdata() and dev_set_drvdata() functions. Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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由 Heiko Carstens 提交于
The slab allocator is earlier available so convert the bootmem allocations to slab/gfp allocations. Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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- 16 6月, 2009 2 次提交
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由 Martin Schwidefsky 提交于
Introduce the power management callbacks to the 3215 console. On suspend the console buffer is flushed to the 3215 device to have an empty console buffer. Printks done while the 3215 device is suspended are buffered in the 64K buffer of the 3215 device. If the buffer is full new messages will push out the oldest messages to make room for the most recent message. On resume the buffered messages are printed. If the system panics before the 3215 device is resumed ccw_device_force_console is used to get the console working again. Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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由 Greg Kroah-Hartman 提交于
In the near future, the driver core is going to not allow direct access to the driver_data pointer in struct device. Instead, the functions dev_get_drvdata() and dev_set_drvdata() should be used. These functions have been around since the beginning, so are backwards compatible with all older kernel versions. Thanks to Sebastian Ott <sebott@linux.vnet.ibm.com> for fixing a few typos in my original version of this patch. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: linux-s390@vger.kernel.org Cc: linux390@de.ibm.com Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
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- 11 10月, 2008 2 次提交
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由 Heiko Carstens 提交于
The 3215 console irq handler used to schedule a tasklet. However the console irq handler also gets called from the infamous cio_tpi() function. Which in turn does something like local_bh_disable() [call console irq handler] _local_bh_enable() _local_bh_enable() prevents execution of softirqs, which is intended within cio_tpi(). However there might be a new softirq pending because irq handler scheduled a tasklet. In order to prevent this behaviour we just get rid of the tasklet. It's not doing much anyway. Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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由 Holger Smolinski 提交于
The s390 console drivers use the unblank callback of the console structure to flush the console buffer. In case of a panic or a reboot the CPU doing the callback can block on the console i/o. The other CPUs in the system continue to work. For panic this is not a good idea. Replace the unblank callback with proper panic/reboot notifier. These get called after all but one CPU have been stopped. Signed-off-by: NHolger Smolinski <Holger.Smolinski@de.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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- 14 7月, 2008 3 次提交
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由 Heiko Carstens 提交于
Most likely it is broken anyway because of the changes in memory detection. Since we can't test it and there are probably better ways that using a P390 card, remove support for it. Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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由 Martin Schwidefsky 提交于
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
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由 Peter Oberparleiter 提交于
Extend the scsw data structure to the format required by fcx. Also provide helper functions for easier access to fields which are present in both the traditional as well as the modified format. Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
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- 30 4月, 2008 1 次提交
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由 Alan Cox 提交于
Put the changes into the drivers first. This will still compile/work but produce a warning if bisected so can still be debugged Signed-off-by: NAlan Cox <alan@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 12 10月, 2007 1 次提交
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由 Cornelia Huck 提交于
The early console device is special as it already has all needed data set and raw3215[0] allocated from con3215_init(). Therefore, it needs special treatment in the probe function so it can be matched with the 3215 driver which is already owning it. Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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- 27 4月, 2007 1 次提交
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由 Heiko Carstens 提交于
We get this: Section mismatch: reference to .init.text:con3270_consetup from .data between 'con3270' (at offset 0x45c8) and 'con3270_fn' Section mismatch: reference to .init.text:con3215_consetup from .data between 'con3215' (at offset 0x4678) and 'raw3215_ccw_driver' Since there is no difference between a non present console setup function and one that returns only 0 remove them. Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
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- 06 2月, 2007 1 次提交
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由 Heiko Carstens 提交于
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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- 14 12月, 2006 1 次提交
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由 Robert P. J. Day 提交于
Run this: #!/bin/sh for f in $(grep -Erl "\([^\)]*\) *k[cmz]alloc" *) ; do echo "De-casting $f..." perl -pi -e "s/ ?= ?\([^\)]*\) *(k[cmz]alloc) *\(/ = \1\(/" $f done And then go through and reinstate those cases where code is casting pointers to non-pointers. And then drop a few hunks which conflicted with outstanding work. Cc: Russell King <rmk@arm.linux.org.uk>, Ian Molton <spyro@f2s.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jeff Dike <jdike@addtoit.com> Cc: Greg KH <greg@kroah.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Paul Fulghum <paulkf@microgate.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Karsten Keil <kkeil@suse.de> Cc: Mauro Carvalho Chehab <mchehab@infradead.org> Cc: Jeff Garzik <jeff@garzik.org> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: Ian Kent <raven@themaw.net> Cc: Steven French <sfrench@us.ibm.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Neil Brown <neilb@cse.unsw.edu.au> Cc: Jaroslav Kysela <perex@suse.cz> Cc: Takashi Iwai <tiwai@suse.de> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 04 12月, 2006 1 次提交
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由 Martin Schwidefsky 提交于
Remove lock pointer from 3215 device structure. Use get_ccwdev_lock for each use of the lock in the ccw-device structure. Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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- 02 10月, 2006 1 次提交
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由 Jeff Dike 提交于
As part of an SMP cleanliness pass over UML, I consted a bunch of structures in order to not have to document their locking. One of these structures was a struct tty_operations. In order to const it in UML without introducing compiler complaints, the declaration of tty_set_operations needs to be changed, and then all of its callers need to be fixed. This patch declares all struct tty_operations in the tree as const. In all cases, they are static and used only as input to tty_set_operations. As an extra check, I ran an i386 allyesconfig build which produced no extra warnings. 53 drivers are affected. I checked the history of a bunch of them, and in most cases, there have been only a handful of maintenance changes in the last six months. serial_core.c was the busiest one that I looked at. Signed-off-by: NJeff Dike <jdike@addtoit.com> Acked-by: NAlan Cox <alan@redhat.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 12 7月, 2006 1 次提交
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由 Heiko Carstens 提交于
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
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- 01 7月, 2006 1 次提交
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由 Jörn Engel 提交于
Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: NAdrian Bunk <bunk@stusta.de>
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- 02 2月, 2006 1 次提交
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由 Peter Oberparleiter 提交于
The return code of ccw_device_probe_console() is not properly handled. It should only return a valid ccw device pointer or a error value converted by ERR_PTR. Fix the console driver code to check with IS_ERR instead against NULL. Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 11 1月, 2006 1 次提交
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由 Alan Cox 提交于
The API and code have been through various bits of initial review by serial driver people but they definitely need to live somewhere for a while so the unconverted drivers can get knocked into shape, existing drivers that have been updated can be better tuned and bugs whacked out. This replaces the tty flip buffers with kmalloc objects in rings. In the normal situation for an IRQ driven serial port at typical speeds the behaviour is pretty much the same, two buffers end up allocated and the kernel cycles between them as before. When there are delays or at high speed we now behave far better as the buffer pool can grow a bit rather than lose characters. This also means that we can operate at higher speeds reliably. For drivers that receive characters in blocks (DMA based, USB and especially virtualisation) the layer allows a lot of driver specific code that works around the tty layer with private secondary queues to be removed. The IBM folks need this sort of layer, the smart serial port people do, the virtualisers do (because a virtualised tty typically operates at infinite speed rather than emulating 9600 baud). Finally many drivers had invalid and unsafe attempts to avoid buffer overflows by directly invoking tty methods extracted out of the innards of work queue structs. These are no longer needed and all go away. That fixes various random hangs with serial ports on overflow. The other change in here is to optimise the receive_room path that is used by some callers. It turns out that only one ldisc uses receive room except asa constant and it updates it far far less than the value is read. We thus make it a variable not a function call. I expect the code to contain bugs due to the size alone but I'll be watching and squashing them and feeding out new patches as it goes. Because the buffers now dynamically expand you should only run out of buffering when the kernel runs out of memory for real. That means a lot of the horrible hacks high performance drivers used to do just aren't needed any more. Description: tty_insert_flip_char is an old API and continues to work as before, as does tty_flip_buffer_push() [this is why many drivers dont need modification]. It does now also return the number of chars inserted There are also tty_buffer_request_room(tty, len) which asks for a buffer block of the length requested and returns the space found. This improves efficiency with hardware that knows how much to transfer. and tty_insert_flip_string_flags(tty, str, flags, len) to insert a string of characters and flags For a smart interface the usual code is len = tty_request_buffer_room(tty, amount_hardware_says); tty_insert_flip_string(tty, buffer_from_card, len); More description! At the moment tty buffers are attached directly to the tty. This is causing a lot of the problems related to tty layer locking, also problems at high speed and also with bursty data (such as occurs in virtualised environments) I'm working on ripping out the flip buffers and replacing them with a pool of dynamically allocated buffers. This allows both for old style "byte I/O" devices and also helps virtualisation and smart devices where large blocks of data suddenely materialise and need storing. So far so good. Lots of drivers reference tty->flip.*. Several of them also call directly and unsafely into function pointers it provides. This will all break. Most drivers can use tty_insert_flip_char which can be kept as an API but others need more. At the moment I've added the following interfaces, if people think more will be needed now is a good time to say int tty_buffer_request_room(tty, size) Try and ensure at least size bytes are available, returns actual room (may be zero). At the moment it just uses the flipbuf space but that will change. Repeated calls without characters being added are not cumulative. (ie if you call it with 1, 1, 1, and then 4 you'll have four characters of space. The other functions will also try and grow buffers in future but this will be a more efficient way when you know block sizes. int tty_insert_flip_char(tty, ch, flag) As before insert a character if there is room. Now returns 1 for success, 0 for failure. int tty_insert_flip_string(tty, str, len) Insert a block of non error characters. Returns the number inserted. int tty_prepare_flip_string(tty, strptr, len) Adjust the buffer to allow len characters to be added. Returns a buffer pointer in strptr and the length available. This allows for hardware that needs to use functions like insl or mencpy_fromio. Signed-off-by: NAlan Cox <alan@redhat.com> Cc: Paul Fulghum <paulkf@microgate.com> Signed-off-by: NHirokazu Takata <takata@linux-m32r.org> Signed-off-by: NSerge Hallyn <serue@us.ibm.com> Signed-off-by: NJeff Dike <jdike@addtoit.com> Signed-off-by: NJohn Hawkes <hawkes@sgi.com> Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: NAdrian Bunk <bunk@stusta.de> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 07 11月, 2005 1 次提交
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由 Jesper Juhl 提交于
This is the drivers/s390/ part of the big kfree cleanup patch. Remove pointless checks for NULL prior to calling kfree() in drivers/s390/. Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com> Acked-by: NCornelia Huck <cohuck@de.ibm.com> Acked-by: NStefan Bader <Stefan.Bader@de.ibm.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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