Costantino Leandro found a bug in tty_find_polling_driver and provided a
patch that fixed the crash but not the underlying bug. This fixes the
underlying bug where the list walk corrupts the values it is using on a
match but then reuses them if the open fails.
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The tty throttling code can race due to the lock drops. It takes very high
loads but this has been observed and verified by Rob Duncan.
The basic problem is that on an SMP box we can go
CPU #1 CPU #2
need to throttle ?
suppose we should buffer space cleared
are we throttled
yes ? - unthrottle
call throttle method
This changeet take the termios lock to protect against this. The termios
lock isn't the initial obvious candidate but many implementations of throttle
methods already need to poke around their own termios structures (and nobody
really locks them against a racing change of flow control).
This does mean that anyone who is setting tty->low_latency = 1 and then
calling tty_flip_buffer_push from their unthrottle method is going to end up
collapsing in a pile of locks. However we've removed all the known bogus
users of low_latency = 1 and such use isn't safe anyway for other reasons so
catching it would be an improvement.
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The legacy TCSETA{,W,F} ioctls failed to set the termio->c_line field
on x86. This adds a missing get_user.
The same ioctls also fail to report faulting user pointers, which
we keep ignoring.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Define ASYNCB_* flags which are bit numbers of the ASYNC_* flags.
This is useful for {test,set,clear}_bit.
Also convert each ASYNC_% to be (1 << ASYNCB_%) and define masks
with the macros, not constants.
Tested with:
#include "PATH_TO_KERNEL/include/linux/serial.h"
static struct {
unsigned int new, old;
} as[] = {
{ ASYNC_HUP_NOTIFY, 0x0001 },
{ ASYNC_FOURPORT, 0x0002 },
...
{ ASYNC_BOOT_ONLYMCA, 0x00400000 },
{ ASYNC_INTERNAL_FLAGS, 0xFFC00000 }
};
...
for (a = 0; a < ARRAY_SIZE(as); a++)
if (as[a].old != as[a].new)
printf("%.8x != %.8x\n", as[a].old, as[a].new);
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Or at least most of it. There are further clean ups possible and there are
are also thing checkpatch moans about that would be silly to "fix".
Also note some FIXME points found as the cleanup was done.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Set up ports right after FW load so that we won't allocate maximal
(64) ports when we use few.
Also remove reading of nports in irq context, since we know it from
initialisation now.
This also fixes a tty ports unregistration on some fail paths and for
Ze which registered 64 and unregistered real port count.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove ugly all-over-the-code casts of ctl_addr to 9060 space.
Add an union to the cyclades_card structure, which contains
a pointer to both 9050 and 9060 spaces.
The 9050 space layout is unknown, so let it still as a void
__iomem pointer.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add receive programmed IO mode to reduce receive latency
when using low data rates. The receive FIFO trigger
level of 128 bytes used in DMA mode creates excessive latency
when operating at low data rates. PIO mode is selected when user
application requests data in blocks of less than 128 bytes.
Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The CDC ACM driver uses the tty layer correctly so needs conversion. Start by
adding and initializing the port structures.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This allows us to clean stuff up, but is probably also going to cause
some app breakage with buggy apps as we now implement proper POSIX behaviour
for USB ports matching all the other ports. This does also mean other apps
that break on USB will now work properly.
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We need this for devices that cannot flush and wait, but which do not order
data and modem events. Without it we will hang up before all the data
clears the hardware. Needed for the USB changes.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some drivers implement this internally, others miss it out. Push the
behaviour into the core code as that way everyone will do it consistently.
Update the dtr rts method to raise or lower depending upon flags. Having a
single method in this style fits most of the implementations more cleanly than
two funtions.
We need this in place before we tackle the USB side
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Alan Cox
Arnd Bergmann
Andre Przywara
Jiri Slaby
Paul Fulghum
Alan Cox