tty/serial: lay the foundations for the next set of reworks
- Stop drivers calling their own flush method indirectly, it obfuscates code
and it will change soon anyway
- A few more lock_kernel paths temporarily needed in some driver internal
waiting code
- Remove private put_char method that does a write call for one char - we
have that anyway
- Most but not yet all of the termios copy under lock fixing (some has other
dependencies to follow)
- Note a few locking bugs in drivers found in the process
- Kill remaining [ab]users of TIOCG/SSOFTCAR in the driver, these must go to
fix the termios locking
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/cyclades.c b/drivers/char/cyclades.c
index e61939d..571e4fa 100644
--- a/drivers/char/cyclades.c
+++ b/drivers/char/cyclades.c
@@ -2522,6 +2522,7 @@
return; /* Just in case.... */
orig_jiffies = jiffies;
+ lock_kernel();
/*
* Set the check interval to be 1/5 of the estimated time to
* send a single character, and make it at least 1. The check
@@ -2573,11 +2574,47 @@
}
/* Run one more char cycle */
msleep_interruptible(jiffies_to_msecs(char_time * 5));
+ unlock_kernel();
#ifdef CY_DEBUG_WAIT_UNTIL_SENT
printk(KERN_DEBUG "Clean (jiff=%lu)...done\n", jiffies);
#endif
}
+static void cy_flush_buffer(struct tty_struct *tty)
+{
+ struct cyclades_port *info = tty->driver_data;
+ struct cyclades_card *card;
+ int channel, retval;
+ unsigned long flags;
+
+#ifdef CY_DEBUG_IO
+ printk(KERN_DEBUG "cyc:cy_flush_buffer ttyC%d\n", info->line);
+#endif
+
+ if (serial_paranoia_check(info, tty->name, "cy_flush_buffer"))
+ return;
+
+ card = info->card;
+ channel = info->line - card->first_line;
+
+ spin_lock_irqsave(&card->card_lock, flags);
+ info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
+ spin_unlock_irqrestore(&card->card_lock, flags);
+
+ if (IS_CYC_Z(*card)) { /* If it is a Z card, flush the on-board
+ buffers as well */
+ spin_lock_irqsave(&card->card_lock, flags);
+ retval = cyz_issue_cmd(card, channel, C_CM_FLUSH_TX, 0L);
+ if (retval != 0) {
+ printk(KERN_ERR "cyc: flush_buffer retval on ttyC%d "
+ "was %x\n", info->line, retval);
+ }
+ spin_unlock_irqrestore(&card->card_lock, flags);
+ }
+ tty_wakeup(tty);
+} /* cy_flush_buffer */
+
+
/*
* This routine is called when a particular tty device is closed.
*/
@@ -2689,8 +2726,7 @@
spin_unlock_irqrestore(&card->card_lock, flags);
shutdown(info);
- if (tty->driver->flush_buffer)
- tty->driver->flush_buffer(tty);
+ cy_flush_buffer(tty);
tty_ldisc_flush(tty);
spin_lock_irqsave(&card->card_lock, flags);
@@ -2881,6 +2917,7 @@
int char_count;
__u32 tx_put, tx_get, tx_bufsize;
+ lock_kernel();
firm_id = card->base_addr + ID_ADDRESS;
zfw_ctrl = card->base_addr +
(readl(&firm_id->zfwctrl_addr) & 0xfffff);
@@ -2898,6 +2935,7 @@
printk(KERN_DEBUG "cyc:cy_chars_in_buffer ttyC%d %d\n",
info->line, info->xmit_cnt + char_count);
#endif
+ unlock_kernel();
return info->xmit_cnt + char_count;
}
#endif /* Z_EXT_CHARS_IN_BUFFER */
@@ -4271,40 +4309,6 @@
}
} /* cy_start */
-static void cy_flush_buffer(struct tty_struct *tty)
-{
- struct cyclades_port *info = tty->driver_data;
- struct cyclades_card *card;
- int channel, retval;
- unsigned long flags;
-
-#ifdef CY_DEBUG_IO
- printk(KERN_DEBUG "cyc:cy_flush_buffer ttyC%d\n", info->line);
-#endif
-
- if (serial_paranoia_check(info, tty->name, "cy_flush_buffer"))
- return;
-
- card = info->card;
- channel = info->line - card->first_line;
-
- spin_lock_irqsave(&card->card_lock, flags);
- info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
- spin_unlock_irqrestore(&card->card_lock, flags);
-
- if (IS_CYC_Z(*card)) { /* If it is a Z card, flush the on-board
- buffers as well */
- spin_lock_irqsave(&card->card_lock, flags);
- retval = cyz_issue_cmd(card, channel, C_CM_FLUSH_TX, 0L);
- if (retval != 0) {
- printk(KERN_ERR "cyc: flush_buffer retval on ttyC%d "
- "was %x\n", info->line, retval);
- }
- spin_unlock_irqrestore(&card->card_lock, flags);
- }
- tty_wakeup(tty);
-} /* cy_flush_buffer */
-
/*
* cy_hangup() --- called by tty_hangup() when a hangup is signaled.
*/