In zs_console_putchar() occurs:
if (zs_transmit_drain(zport, irq))
write_zsdata(zport, ch);
However if in zs_transmit_drain() no empty Tx Buffer occurs, limit reaches
-1 => true, and the write still occurs.
This patch changes postfix to prefix decrements in this and similar
functions to prevent similar mistakes in the future. This decreases the
iterations with one but the chosen loop count was arbitrary anyway.
In sunhv limit reaches -1, not 0, so the test is off by one.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Today's linux-next build (sparc64 defconfig) failed like this:
drivers/serial/sunhv.c: In function `receive_chars':
drivers/serial/sunhv.c:188: error: structure has no member named `tty'
drivers/serial/sunsu.c: In function `receive_chars':
drivers/serial/sunsu.c:314: error: structure has no member named `tty'
drivers/serial/sunsab.c: In function `receive_chars':
drivers/serial/sunsab.c:121: error: structure has no member named `tty'
I applied the following patch (which, again, may not be correct).
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch against 2.6.23 sparc-2.6.git contains a number of minor
cleanups of the sparc serial drivers. Initially I fixed this build
warning:
WARNING: vmlinux.o(.text+0x107a2c): Section mismatch: reference to .init.text:add_preferred_console (between 'sunserial_console_match' and 'sunserial_console_termios')
which is done by declaring sunserial_console_match() as __init. This
resulted in build warnings on sunserial_current_minor. To resolve
these the variable was changed so it is no longer global, and to hide
operations on it inside 2 new functions. These functions handle the
UART minor handling code that is common to all sparc serial drivers.
These changes allowed to clean up the uart counters in all the sparc
serial drivers, and the administration of minor device numbers.
Lastly, sunserial_console_termios() does not need to be exported since
it is only called from non-modular code.
Sadly, the following build warning still exists:
WARNING: vmlinux.o(__ksymtab+0x2910): Section mismatch: reference to .init.text:sunserial_console_match (between '__ksymtab_sunserial_console_match' and '__ksymtab_sunserial_unregister_minors')
This could be resolved by not exporting sunserial_console_match(), but
this is not possible at the moment because it is being called from
modular code. On the other hand, this is a bogus warning since it
comes from a ksymtab section.
Signed-off-by: Martin Habets <errandir_news@mph.eclipse.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current scheme works on static interpretation of text names, which
is wrong.
The output-device setting, for example, must be resolved via an alias
or similar to a full path name to the console device.
Paths also contain an optional set of 'options', which starts with a
colon at the end of the path. The option area is used to specify
which of two serial ports ('a' or 'b') the path refers to when a
device node drives multiple ports. 'a' is assumed if the option
specification is missing.
This was caught by the UltraSPARC-T1 simulator. The 'output-device'
property was set to 'ttya' and we didn't pick upon the fact that this
is an OBP alias set to '/virtual-devices/console'. Instead we saw it
as the first serial console device, instead of the hypervisor console.
The infrastructure is now there to take advantage of this to resolve
the console correctly even in multi-head situations in fbcon too.
Thanks to Greg Onufer for the bug report.
Signed-off-by: David S. Miller <davem@davemloft.net>
Mixing putchar() and write() hvcalls does not work %100
correctly. But we should be using write() all the time
if we can, even from ->start_tx(), anyways.
Signed-off-by: David S. Miller <davem@davemloft.net>
Mirror the logic in 8250 for proper console write locking
when SYSRQ is triggered or an OOPS is in progress.
Signed-off-by: David S. Miller <davem@davemloft.net>
Hypervisor interfaces need to be negotiated in order to use
some API calls reliably. So add a small set of interfaces
to request API versions and query current settings.
This allows us to fix some bugs in the hypervisor console:
1) If we can negotiate API group CORE of at least major 1
minor 1 we can use con_read and con_write which can improve
console performance quite a bit.
2) When we do a console write request, we should hold the
spinlock around the whole request, not a byte at a time.
What would happen is that it's easy for output from
different cpus to get mixed with each other.
3) Use consistent udelay() based polling, udelay(1) each
loop with a limit of 1000 polls to handle stuck hypervisor
console.
Signed-off-by: David S. Miller <davem@davemloft.net>
This is the grungy swap all the occurrences in the right places patch that
goes with the updates. At this point we have the same functionality as
before (except that sgttyb() returns speeds not zero) and are ready to
begin turning new stuff on providing nobody reports lots of bugs
If you are a tty driver author converting an out of tree driver the only
impact should be termios->ktermios name changes for the speed/property
setting functions from your upper layers.
If you are implementing your own TCGETS function before then your driver
was broken already and its about to get a whole lot more painful for you so
please fix it 8)
Also fill in c_ispeed/ospeed on init for most devices, although the current
code will do this for you anyway but I'd like eventually to lose that extra
paranoia
[akpm@osdl.org: bluetooth fix]
[mp3@de.ibm.com: sclp fix]
[mp3@de.ibm.com: warning fix for tty3270]
[hugh@veritas.com: fix tty_ioctl powerpc build]
[jdike@addtoit.com: uml: fix ->set_termios declaration]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.
The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around. On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).
Where appropriate, an arch may override the generic storage facility and do
something different with the variable. On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.
Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions. Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller. A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.
I've build this code with allyesconfig for x86_64 and i386. I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.
This will affect all archs. Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:
struct pt_regs *old_regs = set_irq_regs(regs);
And put the old one back at the end:
set_irq_regs(old_regs);
Don't pass regs through to generic_handle_irq() or __do_IRQ().
In timer_interrupt(), this sort of change will be necessary:
- update_process_times(user_mode(regs));
- profile_tick(CPU_PROFILING, regs);
+ update_process_times(user_mode(get_irq_regs()));
+ profile_tick(CPU_PROFILING);
I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().
Some notes on the interrupt handling in the drivers:
(*) input_dev() is now gone entirely. The regs pointer is no longer stored in
the input_dev struct.
(*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
something different depending on whether it's been supplied with a regs
pointer or not.
(*) Various IRQ handler function pointers have been moved to type
irq_handler_t.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
Because we play this trick where we use ttyS? in increasing minor
numbers for different sunfoo.c drivers, we have to inform the TTY
layer of this.
Do so by setting the tty->name_base appropriately.
Probably there should be a generic way to do this in the serial core,
but for now...
Signed-off-by: David S. Miller <davem@davemloft.net>
Caller takes the lock already.
Also, fixup the poll loop in sunhv_break_ctl(). Just
like in console write, we udelay(2) and use a loop
limit of 1000000 iterations.
Signed-off-by: David S. Miller <davem@davemloft.net>
By calling uart_handle_break(). We'll still do the
"sun_do_break()" handling if the user gives two
breaks in a row.
We should probably do this in the other Sparc serial
drivers too.
Signed-off-by: David S. Miller <davem@davemloft.net>
Until the uart is openned, port->info is NULL.
Also, init the port->irq properly and give a non-zero
port->membase so that the uart device reporting is done.
Signed-off-by: David S. Miller <davem@davemloft.net>
Add udelay to polling console write loop, and increment
the loop limit.
Name the device "ttyHV" and pass that to add_preferred_console()
when we're using hypervisor console.
Kill sunhv_console_setup(), it's empty.
Handle the case where we don't want to use hypervisor console.
(ie. we have a head attached to a sun4v machine)
Signed-off-by: David S. Miller <davem@davemloft.net>
Since it can do things like BREAK and HUP, we implement
this as a serial uart driver.
This still needs interrupt probing code, as I haven't figured
out how interrupts will work or be probed for on SUN4V yet.
Signed-off-by: David S. Miller <davem@davemloft.net>
Roel Kluin