#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
void gs_put_char(struct tty_struct * tty, unsigned char ch)
{
struct gs_port *port;
- DECL
func_enter ();
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;
}
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.
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
}
-static unsigned int gs_baudrates[] = {
- 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
- 9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600
-};
-
-
void gs_set_termios (struct tty_struct * tty,
struct ktermios * old_termios)
{
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");
baudrate = tty_get_baud_rate(tty);
- baudrate = gs_baudrates[baudrate];
if ((tiosp->c_cflag & CBAUD) == B38400) {
if ( (port->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
baudrate = 57600;
projects / linux-2.6-omap-h63xx.git / blobdiff