[PATCH] dvb: ttpci: fix timeout handling to be save with PREEMPT

Timeout handling fixed, especially for preemtible kernels and/or high system
load.

Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 49 insertions, 23 deletions

diff --git a/drivers/media/dvb/ttpci/av7110_hw.c b/drivers/media/dvb/ttpci/av7110_hw.c
index aa1efce6cb31..1220826696c5 100644
--- a/drivers/media/dvb/ttpci/av7110_hw.c
+++ b/drivers/media/dvb/ttpci/av7110_hw.c
@@ -308,6 +308,7 @@ int av7110_wait_msgstate(struct av7110 *av7110, u16 flags)
 {
         unsigned long start;
         u32 stat;
+        int err;
 
         if (FW_VERSION(av7110->arm_app) <= 0x261c) {
                 /* not supported by old firmware */
@@ -318,14 +319,14 @@ int av7110_wait_msgstate(struct av7110 *av7110, u16 flags)
         /* new firmware */
         start = jiffies;
         for (;;) {
+                err = time_after(jiffies, start + ARM_WAIT_FREE);
                 if (down_interruptible(&av7110->dcomlock))
                         return -ERESTARTSYS;
                 stat = rdebi(av7110, DEBINOSWAP, MSGSTATE, 0, 2);
                 up(&av7110->dcomlock);
-                if ((stat & flags) == 0) {
+                if ((stat & flags) == 0)
                         break;
-                }
-                if (time_after(jiffies, start + ARM_WAIT_FREE)) {
+                if (err) {
                         printk(KERN_ERR "%s: timeout waiting for MSGSTATE %04x\n",
                                 __FUNCTION__, stat & flags);
                         return -ETIMEDOUT;
@@ -342,6 +343,7 @@ static int __av7110_send_fw_cmd(struct av7110 *av7110, u16* buf, int length)
         char *type = NULL;
         u16 flags[2] = {0, 0};
         u32 stat;
+        int err;
 
 //      dprintk(4, "%p\n", av7110);
 
@@ -351,8 +353,11 @@ static int __av7110_send_fw_cmd(struct av7110 *av7110, u16* buf, int length)
         }
 
         start = jiffies;
-        while (rdebi(av7110, DEBINOSWAP, COMMAND, 0, 2 )) {
-                if (time_after(jiffies, start + ARM_WAIT_FREE)) {
+        while (1) {
+                err = time_after(jiffies, start + ARM_WAIT_FREE);
+                if (rdebi(av7110, DEBINOSWAP, COMMAND, 0, 2) == 0)
+                        break;
+                if (err) {
                         printk(KERN_ERR "dvb-ttpci: %s(): timeout waiting for COMMAND idle\n", __FUNCTION__);
                         return -ETIMEDOUT;
                 }
@@ -363,8 +368,11 @@ static int __av7110_send_fw_cmd(struct av7110 *av7110, u16* buf, int length)
 
 #ifndef _NOHANDSHAKE
         start = jiffies;
-        while (rdebi(av7110, DEBINOSWAP, HANDSHAKE_REG, 0, 2 )) {
-                if (time_after(jiffies, start + ARM_WAIT_SHAKE)) {
+        while (1) {
+                err = time_after(jiffies, start + ARM_WAIT_SHAKE);
+                if (rdebi(av7110, DEBINOSWAP, HANDSHAKE_REG, 0, 2) == 0)
+                        break;
+                if (err) {
                         printk(KERN_ERR "dvb-ttpci: %s(): timeout waiting for HANDSHAKE_REG\n", __FUNCTION__);
                         return -ETIMEDOUT;
                 }
@@ -401,6 +409,7 @@ static int __av7110_send_fw_cmd(struct av7110 *av7110, u16* buf, int length)
                 /* non-immediate COMMAND type */
                 start = jiffies;
                 for (;;) {
+                        err = time_after(jiffies, start + ARM_WAIT_FREE);
                         stat = rdebi(av7110, DEBINOSWAP, MSGSTATE, 0, 2);
                         if (stat & flags[0]) {
                                 printk(KERN_ERR "%s: %s QUEUE overflow\n",
@@ -409,7 +418,7 @@ static int __av7110_send_fw_cmd(struct av7110 *av7110, u16* buf, int length)
                         }
                         if ((stat & flags[1]) == 0)
                                 break;
-                        if (time_after(jiffies, start + ARM_WAIT_FREE)) {
+                        if (err) {
                                 printk(KERN_ERR "%s: timeout waiting on busy %s QUEUE\n",
                                         __FUNCTION__, type);
                                 return -ETIMEDOUT;
@@ -432,12 +441,13 @@ static int __av7110_send_fw_cmd(struct av7110 *av7110, u16* buf, int length)
 
 #ifdef COM_DEBUG
         start = jiffies;
-        while (rdebi(av7110, DEBINOSWAP, COMMAND, 0, 2 )) {
-                if (time_after(jiffies, start + ARM_WAIT_FREE)) {
+        while (1) {
+                err = time_after(jiffies, start + ARM_WAIT_FREE);
+                if (rdebi(av7110, DEBINOSWAP, COMMAND, 0, 2) == 0)
+                        break;
+                if (err) {
                         printk(KERN_ERR "dvb-ttpci: %s(): timeout waiting for COMMAND %d to complete\n",
-                               __FUNCTION__,
-                                (buf[0] >> 8) & 0xff
-                               );
+                               __FUNCTION__, (buf[0] >> 8) & 0xff);
                         return -ETIMEDOUT;
                 }
                 msleep(1);
@@ -553,8 +563,11 @@ int av7110_fw_request(struct av7110 *av7110, u16 *request_buf,
         }
 
         start = jiffies;
-        while (rdebi(av7110, DEBINOSWAP, COMMAND, 0, 2)) {
-                if (time_after(jiffies, start + ARM_WAIT_FREE)) {
+        while (1) {
+                err = time_after(jiffies, start + ARM_WAIT_FREE);
+                if (rdebi(av7110, DEBINOSWAP, COMMAND, 0, 2) == 0)
+                        break;
+                if (err) {
                         printk(KERN_ERR "%s: timeout waiting for COMMAND to complete\n", __FUNCTION__);
                         up(&av7110->dcomlock);
                         return -ETIMEDOUT;
@@ -566,8 +579,11 @@ int av7110_fw_request(struct av7110 *av7110, u16 *request_buf,
 
 #ifndef _NOHANDSHAKE
         start = jiffies;
-        while (rdebi(av7110, DEBINOSWAP, HANDSHAKE_REG, 0, 2 )) {
-                if (time_after(jiffies, start + ARM_WAIT_SHAKE)) {
+        while (1) {
+                err = time_after(jiffies, start + ARM_WAIT_SHAKE);
+                if (rdebi(av7110, DEBINOSWAP, HANDSHAKE_REG, 0, 2) == 0)
+                        break;
+                if (err) {
                         printk(KERN_ERR "%s: timeout waiting for HANDSHAKE_REG\n", __FUNCTION__);
                         up(&av7110->dcomlock);
                         return -ETIMEDOUT;
@@ -707,12 +723,16 @@ static inline int SetFont(struct av7110 *av7110, u8 windownr, u8 fontsize,
 static int FlushText(struct av7110 *av7110)
 {
         unsigned long start;
+        int err;
 
         if (down_interruptible(&av7110->dcomlock))
                 return -ERESTARTSYS;
         start = jiffies;
-        while (rdebi(av7110, DEBINOSWAP, BUFF1_BASE, 0, 2)) {
-                if (time_after(jiffies, start + ARM_WAIT_OSD)) {
+        while (1) {
+                err = time_after(jiffies, start + ARM_WAIT_OSD);
+                if (rdebi(av7110, DEBINOSWAP, BUFF1_BASE, 0, 2) == 0)
+                        break;
+                if (err) {
                         printk(KERN_ERR "dvb-ttpci: %s(): timeout waiting for BUFF1_BASE == 0\n",
                                __FUNCTION__);
                         up(&av7110->dcomlock);
@@ -735,8 +755,11 @@ static int WriteText(struct av7110 *av7110, u8 win, u16 x, u16 y, u8* buf)
                 return -ERESTARTSYS;
 
         start = jiffies;
-        while (rdebi(av7110, DEBINOSWAP, BUFF1_BASE, 0, 2)) {
-                if (time_after(jiffies, start + ARM_WAIT_OSD)) {
+        while (1) {
+                ret = time_after(jiffies, start + ARM_WAIT_OSD);
+                if (rdebi(av7110, DEBINOSWAP, BUFF1_BASE, 0, 2) == 0)
+                        break;
+                if (ret) {
                         printk(KERN_ERR "dvb-ttpci: %s: timeout waiting for BUFF1_BASE == 0\n",
                                __FUNCTION__);
                         up(&av7110->dcomlock);
@@ -746,8 +769,11 @@ static int WriteText(struct av7110 *av7110, u8 win, u16 x, u16 y, u8* buf)
         }
 #ifndef _NOHANDSHAKE
         start = jiffies;
-        while (rdebi(av7110, DEBINOSWAP, HANDSHAKE_REG, 0, 2)) {
-                if (time_after(jiffies, start + ARM_WAIT_SHAKE)) {
+        while (1) {
+                ret = time_after(jiffies, start + ARM_WAIT_SHAKE);
+                if (rdebi(av7110, DEBINOSWAP, HANDSHAKE_REG, 0, 2) == 0)
+                        break;
+                if (ret) {
                         printk(KERN_ERR "dvb-ttpci: %s: timeout waiting for HANDSHAKE_REG\n",
                                __FUNCTION__);
                         up(&av7110->dcomlock);