The patch titled
genericserial: remove bogus optimisation check and dead code paths
has been added to the -mm tree. Its filename is
genericserial-remove-bogus-optimisation-check-and-dead-code-paths.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: genericserial: remove bogus optimisation check and dead code paths
From: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
We've been using the 'new locking' for a long time now so it seems
pointless keeping the old one around. Remove it and undo the macros it
uses back into real code for readability. Remove the bogus 'no termios
change' checks.
Signed-off-by: Alan Cox <alan@xxxxxxxxxx>
Cc: Morten Helgesen <morten@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/char/generic_serial.c | 120 --------------------------------
1 files changed, 3 insertions(+), 117 deletions(-)
diff -puN drivers/char/generic_serial.c~genericserial-remove-bogus-optimisation-check-and-dead-code-paths drivers/char/generic_serial.c
--- a/drivers/char/generic_serial.c~genericserial-remove-bogus-optimisation-check-and-dead-code-paths
+++ a/drivers/char/generic_serial.c
@@ -43,16 +43,6 @@ static int gs_debug;
#define func_enter() gs_dprintk (GS_DEBUG_FLOW, "gs: enter %s\n", __FUNCTION__)
#define func_exit() gs_dprintk (GS_DEBUG_FLOW, "gs: exit %s\n", __FUNCTION__)
-#define NEW_WRITE_LOCKING 1
-#if NEW_WRITE_LOCKING
-#define DECL /* Nothing */
-#define LOCKIT mutex_lock(& port->port_write_mutex);
-#define RELEASEIT mutex_unlock(&port->port_write_mutex);
-#else
-#define DECL unsigned long flags;
-#define LOCKIT save_flags (flags);cli ()
-#define RELEASEIT restore_flags (flags)
-#endif
#define RS_EVENT_WRITE_WAKEUP 1
@@ -62,7 +52,6 @@ module_param(gs_debug, int, 0644);
void gs_put_char(struct tty_struct * tty, unsigned char ch)
{
struct gs_port *port;
- DECL
func_enter ();
@@ -75,11 +64,11 @@ void gs_put_char(struct tty_struct * tty
if (! (port->flags & ASYNC_INITIALIZED)) return;
/* Take a lock on the serial tranmit buffer! */
- LOCKIT;
+ mutex_lock(& port->port_write_mutex);
if (port->xmit_cnt >= SERIAL_XMIT_SIZE - 1) {
/* Sorry, buffer is full, drop character. Update statistics???? -- REW */
- RELEASEIT;
+ mutex_unlock(&port->port_write_mutex);
return;
}
@@ -87,13 +76,11 @@ void gs_put_char(struct tty_struct * tty
port->xmit_head &= SERIAL_XMIT_SIZE - 1;
port->xmit_cnt++; /* Characters in buffer */
- RELEASEIT;
+ mutex_unlock(&port->port_write_mutex);
func_exit ();
}
-#ifdef NEW_WRITE_LOCKING
-
/*
> Problems to take into account are:
> -1- Interrupts that empty part of the buffer.
@@ -166,90 +153,6 @@ int gs_write(struct tty_struct * tty,
func_exit ();
return total;
}
-#else
-/*
-> Problems to take into account are:
-> -1- Interrupts that empty part of the buffer.
-> -2- page faults on the access to userspace.
-> -3- Other processes that are also trying to do a "write".
-*/
-
-int gs_write(struct tty_struct * tty,
- const unsigned char *buf, int count)
-{
- struct gs_port *port;
- int c, total = 0;
- int t;
- unsigned long flags;
-
- func_enter ();
-
- /* The standard serial driver returns 0 in this case.
- That sounds to me as "No error, I just didn't get to writing any
- bytes. Feel free to try again."
- The "official" way to write n bytes from buf is:
-
- for (nwritten = 0;nwritten < n;nwritten += rv) {
- rv = write (fd, buf+nwritten, n-nwritten);
- if (rv < 0) break; // Error: bail out. //
- }
-
- which will loop endlessly in this case. The manual page for write
- agrees with me. In practise almost everybody writes
- "write (fd, buf,n);" but some people might have had to deal with
- incomplete writes in the past and correctly implemented it by now...
- */
-
- if (!tty) return -EIO;
-
- port = tty->driver_data;
- if (!port || !port->xmit_buf)
- return -EIO;
-
- local_save_flags(flags);
- while (1) {
- cli();
- c = count;
-
- /* This is safe because we "OWN" the "head". Noone else can
- change the "head": we own the port_write_mutex. */
- /* Don't overrun the end of the buffer */
- t = SERIAL_XMIT_SIZE - port->xmit_head;
- if (t < c) c = t;
-
- /* This is safe because the xmit_cnt can only decrease. This
- would increase "t", so we might copy too little chars. */
- /* Don't copy past the "head" of the buffer */
- t = SERIAL_XMIT_SIZE - 1 - port->xmit_cnt;
- if (t < c) c = t;
-
- /* Can't copy more? break out! */
- if (c <= 0) {
- local_restore_flags(flags);
- break;
- }
- memcpy(port->xmit_buf + port->xmit_head, buf, c);
- port->xmit_head = ((port->xmit_head + c) &
- (SERIAL_XMIT_SIZE-1));
- port->xmit_cnt += c;
- local_restore_flags(flags);
- buf += c;
- count -= c;
- total += c;
- }
-
- if (port->xmit_cnt &&
- !tty->stopped &&
- !tty->hw_stopped &&
- !(port->flags & GS_TX_INTEN)) {
- port->flags |= GS_TX_INTEN;
- port->rd->enable_tx_interrupts (port);
- }
- func_exit ();
- return total;
-}
-
-#endif
@@ -737,23 +640,6 @@ void gs_set_termios (struct tty_struct *
gs_dprintk (GS_DEBUG_TERMIOS, "termios structure (%p):\n", tiosp);
}
- /* This is an optimization that is only allowed for dumb cards */
- /* Smart cards require knowledge of iflags and oflags too: that
- might change hardware cooking mode.... */
- if (old_termios) {
- if( (tiosp->c_iflag == old_termios->c_iflag)
- && (tiosp->c_oflag == old_termios->c_oflag)
- && (tiosp->c_cflag == old_termios->c_cflag)
- && (tiosp->c_lflag == old_termios->c_lflag)
- && (tiosp->c_line == old_termios->c_line)
- && (memcmp(tiosp->c_cc, old_termios->c_cc, NCC) == 0)) {
- gs_dprintk(GS_DEBUG_TERMIOS, "gs_set_termios: optimized away\n");
- return /* 0 */;
- }
- } else
- gs_dprintk(GS_DEBUG_TERMIOS, "gs_set_termios: no old_termios: "
- "no optimization\n");
-
if(old_termios && (gs_debug & GS_DEBUG_TERMIOS)) {
if(tiosp->c_iflag != old_termios->c_iflag) printk("c_iflag changed\n");
if(tiosp->c_oflag != old_termios->c_oflag) printk("c_oflag changed\n");
_
Patches currently in -mm which might be from alan@xxxxxxxxxxxxxxxxxxx are
lots-of-architectures-enable-arbitary-speed-tty-support.patch
powerpc-enable-arbitary-speed-tty-ioctls-and-split.patch
ia64-arbitary-speed-tty-ioctl-support.patch
git-libata-all.patch
libata-add-ich8m-pciids-to-ata_piix.patch
libata-add-irq_flags-to-struct-pata_platform_info.patch
libata-add-irq_flags-to-struct-pata_platform_info-fix.patch
pata_pdc202xx_old-correct-cable-detect-logic.patch
libata-fix-hopefully-all-the-remaining-problems-with.patch
testing-patch-for-ali-pata-fixes-hopefully-for-the-problems-with-atapi-dma.patch
pata_ali-more-work.patch
tty-add-the-new-ioctls-and-definitionto-the-mips.patch
rfcomm-hangup-ttys-before-releasing-rfcomm_dev.patch
fix-gregkh-pci-pci-syscallc-switch-to-refcounting-api.patch
add-pci_try_set_mwi.patch
git-scsi-misc.patch
ppa-coding-police-and-printk-levels.patch
x86-64-disable-the-gart-in-shutdown.patch
x86_84-move-iommu-declaration-from-proto-to-iommuh.patch
x86_84-move-iommu-declaration-from-proto-to-iommuh-fix.patch
xtensa-enable-arbitary-tty-speed-setting-ioctls.patch
blackfin-enable-arbitary-speed-serial-setting.patch
h8300-enable-arbitary-speed-tty-port-setup.patch
arm26-enable-arbitary-speed-tty-ioctls-and-split.patch
m32r-enable-arbitary-speed-tty-rate-setting.patch
etrax-enable-arbitary-speed-setting-on-tty-ports.patch
v850-enable-arbitary-speed-tty-ioctls.patch
doc-kernel-parameters-use-x86-32-tag-instead-of-ia-32.patch
make-proc-tty-drivers-use-seq_list_xxx-helpers.patch
update-zilog-timeout.patch
edd-switch-to-pci_get-based-api.patch
mpu401-warning-fixes.patch
char-tty_ioctl-use-wait_event_interruptible_timeout.patch
char-tty_ioctl-little-whitespace-cleanup.patch
intel-rng-undo-mess-made-by-an-80-column-extremist.patch
improve-behaviour-of-spurious-irq-detect.patch
audit-add-tty-input-auditing.patch
audit-add-tty-input-auditing-fix.patch
audit-add-tty-input-auditing-fix-2.patch
revert-vanishing-ioctl-handler-debugging.patch
amiserial-remove-incorrect-no-termios-change-check.patch
genericserial-remove-bogus-optimisation-check-and-dead-code-paths.patch
i2o_cfg_passthru-cleanup.patch
i2o_cfg_passthru-cleanup-fix.patch
wrong-memory-access-in-i2o_block_device_lock.patch
i2o-message-leak-in-i2o_msg_post_wait_mem.patch
i2o-proc-reading-oops.patch
i2o-debug-output-cleanup.patch
coredump-masking-bound-suid_dumpable-sysctl.patch
coredump-masking-reimplementation-of-dumpable-using-two-flags.patch
coredump-masking-reimplementation-of-dumpable-using-two-flags-fix.patch
coredump-masking-add-an-interface-for-core-dump-filter.patch
coredump-masking-elf-enable-core-dump-filtering.patch
coredump-masking-elf-fdpic-remove-an-unused-argument.patch
coredump-masking-elf-fdpic-enable-core-dump-filtering.patch
coredump-masking-documentation-for-proc-pid-coredump_filter.patch
driver-edac-add-mips-and-ppc-visibility.patch
driver-edac-mod-race-fix-i82875p.patch
driver-edac-fix-ignored-return-i82875p.patch
include-linux-pci_id-h-add-amd-northbridge-defines.patch
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