[PATCH 14/68] istallion: use bit ops for the board flags

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From: Greg Kroah-Hartman
Date: Tuesday, August 10, 2010 - 2:58 pm

From: Alan Cox <alan@linux.intel.com>

This lets us avoid problems with races on the flag changes

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/char/istallion.c  |   36 ++++++++++++++++++------------------
 include/linux/istallion.h |    2 +-
 2 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/drivers/char/istallion.c b/drivers/char/istallion.c
index 750650c..5e9a81d 100644
--- a/drivers/char/istallion.c
+++ b/drivers/char/istallion.c
@@ -14,7 +14,6 @@
  *	the Free Software Foundation; either version 2 of the License, or
  *	(at your option) any later version.
  *
- *	FIXME: brdp->state needs proper locking.
  */
 
 /*****************************************************************************/
@@ -204,9 +203,9 @@ static int		stli_shared;
  *	the board has been detected, and whether it is actually running a slave
  *	or not.
  */
-#define	BST_FOUND	0x1
-#define	BST_STARTED	0x2
-#define	BST_PROBED	0x4
+#define	BST_FOUND	0
+#define	BST_STARTED	1
+#define	BST_PROBED	2
 
 /*
  *	Define the set of port state flags. These are marked for internal
@@ -817,7 +816,7 @@ static int stli_open(struct tty_struct *tty, struct file *filp)
 	brdp = stli_brds[brdnr];
 	if (brdp == NULL)
 		return -ENODEV;
-	if ((brdp->state & BST_STARTED) == 0)
+	if (!test_bit(BST_STARTED, &brdp->state))
 		return -ENODEV;
 	portnr = MINOR2PORT(minordev);
 	if (portnr > brdp->nrports)
@@ -1847,7 +1846,7 @@ static void stli_portinfo(struct seq_file *m, struct stlibrd *brdp, struct stlip
 	rc = stli_portcmdstats(NULL, portp);
 
 	uart = "UNKNOWN";
-	if (brdp->state & BST_STARTED) {
+	if (test_bit(BST_STARTED, &brdp->state)) {
 		switch (stli_comstats.hwid) {
 		case 0:	uart = "2681"; break;
 		case 1:	uart = "SC26198"; break;
@@ -1856,7 +1855,7 @@ static void stli_portinfo(struct seq_file *m, struct stlibrd *brdp, struct stlip
 	}
 	seq_printf(m, "%d: uart:%s ", portnr, uart);
 
-	if ((brdp->state & BST_STARTED) && (rc >= 0)) {
+	if (test_bit(BST_STARTED, &brdp->state) && rc >= 0) {
 		char sep;
 
 		seq_printf(m, "tx:%d rx:%d", (int) stli_comstats.txtotal,
@@ -2356,7 +2355,7 @@ static void stli_poll(unsigned long arg)
 		brdp = stli_brds[brdnr];
 		if (brdp == NULL)
 			continue;
-		if ((brdp->state & BST_STARTED) == 0)
+		if (!test_bit(BST_STARTED, &brdp->state))
 			continue;
 
 		spin_lock(&brd_lock);
@@ -3141,7 +3140,7 @@ static int stli_initecp(struct stlibrd *brdp)
 	}
 
 
-	brdp->state |= BST_FOUND;
+	set_bit(BST_FOUND, &brdp->state);
 	return 0;
 err_unmap:
 	iounmap(brdp->membase);
@@ -3298,7 +3297,7 @@ static int stli_initonb(struct stlibrd *brdp)
 	brdp->panels[0] = brdp->nrports;
 
 
-	brdp->state |= BST_FOUND;
+	set_bit(BST_FOUND, &brdp->state);
 	return 0;
 err_unmap:
 	iounmap(brdp->membase);
@@ -3408,7 +3407,7 @@ stli_donestartup:
 	spin_unlock_irqrestore(&brd_lock, flags);
 
 	if (rc == 0)
-		brdp->state |= BST_STARTED;
+		set_bit(BST_STARTED, &brdp->state);
 
 	if (! stli_timeron) {
 		stli_timeron++;
@@ -3711,7 +3710,7 @@ static int __devinit stli_pciprobe(struct pci_dev *pdev,
 	if (retval)
 		goto err_null;
 
-	brdp->state |= BST_PROBED;
+	set_bit(BST_PROBED, &brdp->state);
 	pci_set_drvdata(pdev, brdp);
 
 	EBRDENABLE(brdp);
@@ -3842,7 +3841,7 @@ static int __init stli_initbrds(void)
 			brdp = stli_brds[i];
 			if (brdp == NULL)
 				continue;
-			if (brdp->state & BST_FOUND) {
+			if (test_bit(BST_FOUND, &brdp->state)) {
 				EBRDENABLE(brdp);
 				brdp->enable = NULL;
 				brdp->disable = NULL;
@@ -4079,7 +4078,7 @@ static int stli_portcmdstats(struct tty_struct *tty, struct stliport *portp)
 		return -ENODEV;
 
 	mutex_lock(&portp->port.mutex);
-	if (brdp->state & BST_STARTED) {
+	if (test_bit(BST_STARTED, &brdp->state)) {
 		if ((rc = stli_cmdwait(brdp, portp, A_GETSTATS,
 		    &stli_cdkstats, sizeof(asystats_t), 1)) < 0) {
 			mutex_unlock(&portp->port.mutex);
@@ -4194,7 +4193,7 @@ static int stli_clrportstats(struct stliport *portp, comstats_t __user *cp)
 
 	mutex_lock(&portp->port.mutex);
 
-	if (brdp->state & BST_STARTED) {
+	if (test_bit(BST_STARTED, &brdp->state)) {
 		if ((rc = stli_cmdwait(brdp, portp, A_CLEARSTATS, NULL, 0, 0)) < 0) {
 			mutex_unlock(&portp->port.mutex);
 			return rc;
@@ -4323,10 +4322,10 @@ static long stli_memioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 		rc = stli_startbrd(brdp);
 		break;
 	case STL_BSTOP:
-		brdp->state &= ~BST_STARTED;
+		clear_bit(BST_STARTED, &brdp->state);
 		break;
 	case STL_BRESET:
-		brdp->state &= ~BST_STARTED;
+		clear_bit(BST_STARTED, &brdp->state);
 		EBRDRESET(brdp);
 		if (stli_shared == 0) {
 			if (brdp->reenable != NULL)
@@ -4382,7 +4381,8 @@ static void istallion_cleanup_isa(void)
 	unsigned int j;
 
 	for (j = 0; (j < stli_nrbrds); j++) {
-		if ((brdp = stli_brds[j]) == NULL || (brdp->state & BST_PROBED))
+		if ((brdp = stli_brds[j]) == NULL ||
+				test_bit(BST_PROBED, &brdp->state))
 			continue;
 
 		stli_cleanup_ports(brdp);
diff --git a/include/linux/istallion.h b/include/linux/istallion.h
index 7faca98..ad700a6 100644
--- a/include/linux/istallion.h
+++ b/include/linux/istallion.h
@@ -86,7 +86,7 @@ struct stlibrd {
 	unsigned long	magic;
 	unsigned int	brdnr;
 	unsigned int	brdtype;
-	unsigned int	state;
+	unsigned long	state;
 	unsigned int	nrpanels;
 	unsigned int	nrports;
 	unsigned int	nrdevs;
-- 
1.7.2

--
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Messages in current thread:
[GIT PATCH] TTY patches for 2.6.36, try 2, Greg KH, (Tue Aug 10, 2:44 pm)
[PATCH 01/68] n_gsm.c: removed duplicated #includes, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 02/68] serial: There's no config CONSOLE, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 03/68] vt: clean up the code - use kernel library, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 04/68] serial: add UART_CAP_EFR and UART_CAP_SLEEP ..., Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 05/68] mrst_max3110: add UART driver for Max3110 on ..., Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 06/68] max3110 sanity check a register, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 07/68] serial: replace open coded mutex with a real ..., Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 08/68] serial: fix wakup races in the mrst_max3110 ..., Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 09/68] tty: Remove Hayes ESP ioctls, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 10/68] tty: remove remaining Hayes ESP ioctls, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 11/68] tty: Add EXTPROC support for LINEMODE, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 12/68] vt/console: try harder to print output when ..., Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 13/68] stallion: prune lock_kernel calls, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 14/68] istallion: use bit ops for the board flags, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 15/68] riscom8: kill use of lock_kernel, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 16/68] isicom: kill off the BKL, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 17/68] rocket: kill BKL, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 18/68] synclink: kill the big kernel lock, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 19/68] cyclades: Kill off BKL usage, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 20/68] epca: Kill the big kernel lock, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 21/68] specialix: Kill the BKL, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 22/68] tty: Fix the digi acceleport driver NULL checks, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 23/68] synclink: reworking locking a bit, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 24/68] tty: serial - fix various misuses/mishandlin ..., Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 25/68] tty: serial - fix tty back references in termios, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 26/68] tty: serial - fix tty referencing in set_ldisc, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 27/68] vc: Locking clean up, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 28/68] tty: Make vt's have a tty_port, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 29/68] tty: Move the vt_tty field from the vc_data ..., Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 30/68] serial: Change the wait for carrier locking, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 31/68] serial: add port helpers, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 32/68] serial: trim locking on the helpers, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 33/68] serial: Use block_til_ready helper, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 34/68] serial: fix termios settings in open, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 35/68] tty: replace BKL with a new tty_lock, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 36/68] tty: never hold BTM while getting tty_mutex, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 37/68] tty: fix console_sem lock order, Greg Kroah-Hartman, (Tue Aug 10, 2:58 pm)
[PATCH 38/68] cdc-acm: remove dead code, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 39/68] tty: introduce wait_event_interruptible_tty, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 40/68] tty: reorder ldisc locking, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 41/68] tty: untangle locking of wait_until_sent, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 42/68] tty: remove tty_lock_nested, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 43/68] tty: implement BTM as mutex instead of BKL, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 44/68] tty: release BTM while sleeping in block_til ..., Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 45/68] 8250: fix set_ldisc operation, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 46/68] tty: avoid recursive BTM in pty_close, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 47/68] serial: max3107: introduce a max3107 driver, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 48/68] serial: max3107: Abstract out the platform s ..., Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 49/68] tty_io: remove casts from void*, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 50/68] vt: Fix warning: statement with no effect du ..., Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 51/68] serial: crisv10: formatting of pointers in p ..., Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 53/68] serial: fix missing bit coverage of ASYNC_FLAGS, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 54/68] serial: general fixes in the serial_rs485 st ..., Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 55/68] serial: mcf: don't take spinlocks in already ..., Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 56/68] serial: MMIO32 support for 8250_early.c, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 57/68] timbuart: use __devinit and __devexit macros ..., Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 58/68] serial: 68328serial.c: remove dead (ALMA_ANS ..., Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 59/68] serial: add support for OX16PCI958 card, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 60/68] mxser: remove unnesesary NULL check, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 61/68] hsu: driver for Medfield High Speed UART device, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 62/68] hsu: add a periodic timer to check dma rx ch ..., Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 63/68] hsu: some code cleanup, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 64/68] hsu: call PCI pm hooks in suspend/resume fun ..., Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 65/68] serial: max3107: Fix gpiolib support, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)
[PATCH 68/68] U6715 16550A serial driver support, Greg Kroah-Hartman, (Tue Aug 10, 2:59 pm)