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Commit 1a76fede authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds
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[PATCH] fix radio_cadet driver locking 

Forward port the replacement to the horribly broken locking in 2.5
radio_cadet driver.
parent 53efd89f
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Showing with 74 additions and 104 deletions
drivers/media/radio/radio-cadet.c
View file @ 1a76fede
......@@ -23,7 +23,9 @@
* 2002-01-17 Adam Belay <ambx1@neo.rr.com>
* Updated to latest pnp code
*
*/
* 2003-01-31 Alan Cox <alan@redhat.com>
* Cleaned up locking, delay code, general odds and ends
*/
#include <linux/module.h> /* Modules */
#include <linux/init.h> /* Initdata */
......@@ -43,11 +45,11 @@ static int users=0;
static int curtuner=0;
static int tunestat=0;
static int sigstrength=0;
static wait_queue_head_t tunerq,rdsq,readq;
static wait_queue_head_t readq;
struct timer_list tunertimer,rdstimer,readtimer;
static __u8 rdsin=0,rdsout=0,rdsstat=0;
static unsigned char rdsbuf[RDS_BUFFER];
static int cadet_lock=0;
static spinlock_t cadet_io_lock;
static int cadet_probe(void);
......@@ -58,37 +60,19 @@ static int cadet_probe(void);
*/
static __u16 sigtable[2][4]={{5,10,30,150},{28,40,63,1000}};
static void cadet_wake(unsigned long qnum)
{
switch(qnum) {
case 0: /* cadet_setfreq */
wake_up(&tunerq);
break;
case 1: /* cadet_getrds */
wake_up(&rdsq);
break;
}
}
static int cadet_getrds(void)
{
int rdsstat=0;
cadet_lock++;
spin_lock(&cadet_io_lock);
outb(3,io); /* Select Decoder Control/Status */
outb(inb(io+1)&0x7f,io+1); /* Reset RDS detection */
cadet_lock--;
init_timer(&rdstimer);
rdstimer.function=cadet_wake;
rdstimer.data=(unsigned long)1;
rdstimer.expires=jiffies+(HZ/10);
init_waitqueue_head(&rdsq);
add_timer(&rdstimer);
sleep_on(&rdsq);
cadet_lock++;
spin_unlock(&cadet_io_lock);
set_current_state(TASK_UNINTERRUPTIBLE);
schedule_timeout(HZ/10);
spin_lock(&cadet_io_lock);
outb(3,io); /* Select Decoder Control/Status */
if((inb(io+1)&0x80)!=0) {
rdsstat|=VIDEO_TUNER_RDS_ON;
......@@ -96,32 +80,24 @@ static int cadet_getrds(void)
if((inb(io+1)&0x10)!=0) {
rdsstat|=VIDEO_TUNER_MBS_ON;
}
cadet_lock--;
spin_unlock(&cadet_io_lock);
return rdsstat;
}
static int cadet_getstereo(void)
{
if(curtuner!=0) { /* Only FM has stereo capability! */
int ret = 0;
if(curtuner != 0) /* Only FM has stereo capability! */
return 0;
}
cadet_lock++;
spin_lock(&cadet_io_lock);
outb(7,io); /* Select tuner control */
if((inb(io+1)&0x40)==0) {
cadet_lock--;
return 1; /* Stereo pilot detected */
}
else {
cadet_lock--;
return 0; /* Mono */
}
if( (inb(io+1) & 0x40) == 0)
ret = 1;
spin_unlock(&cadet_io_lock);
return ret;
}
static unsigned cadet_gettune(void)
{
int curvol,i;
......@@ -130,7 +106,9 @@ static unsigned cadet_gettune(void)
/*
* Prepare for read
*/
cadet_lock++;
spin_lock(&cadet_io_lock);
outb(7,io); /* Select tuner control */
curvol=inb(io+1); /* Save current volume/mute setting */
outb(0x00,io+1); /* Ensure WRITE-ENABLE is LOW */
......@@ -152,13 +130,11 @@ static unsigned cadet_gettune(void)
* Restore volume/mute setting
*/
outb(curvol,io+1);
cadet_lock--;
spin_unlock(&cadet_io_lock);
return fifo;
}
static unsigned cadet_getfreq(void)
{
int i;
......@@ -191,14 +167,13 @@ static unsigned cadet_getfreq(void)
return freq;
}
static void cadet_settune(unsigned fifo)
{
int i;
unsigned test;
cadet_lock++;
spin_lock(&cadet_io_lock);
outb(7,io); /* Select tuner control */
/*
* Write the shift register
......@@ -217,11 +192,9 @@ static void cadet_settune(unsigned fifo)
test=0x1c|((fifo>>23)&0x02);
outb(test,io+1);
}
cadet_lock--;
spin_unlock(&cadet_io_lock);
}
static void cadet_setfreq(unsigned freq)
{
unsigned fifo;
......@@ -253,92 +226,90 @@ static void cadet_setfreq(unsigned freq)
/*
* Save current volume/mute setting
*/
cadet_lock++;
spin_lock(&cadet_io_lock);
outb(7,io); /* Select tuner control */
curvol=inb(io+1);
spin_unlock(&cadet_io_lock);
/*
* Tune the card
*/
for(j=3;j>-1;j--) {
cadet_settune(fifo|(j<<16));
spin_lock(&cadet_io_lock);
outb(7,io); /* Select tuner control */
outb(curvol,io+1);
cadet_lock--;
init_timer(&tunertimer);
tunertimer.function=cadet_wake;
tunertimer.data=(unsigned long)0;
tunertimer.expires=jiffies+(HZ/10);
init_waitqueue_head(&tunerq);
add_timer(&tunertimer);
sleep_on(&tunerq);
spin_unlock(&cadet_io_lock);
set_current_state(TASK_UNINTERRUPTIBLE);
schedule_timeout(HZ/10);
cadet_gettune();
if((tunestat&0x40)==0) { /* Tuned */
if((tunestat & 0x40) == 0) { /* Tuned */
sigstrength=sigtable[curtuner][j];
return;
}
cadet_lock++;
}
cadet_lock--;
sigstrength=0;
}
static int cadet_getvol(void)
{
cadet_lock++;
int ret = 0;
spin_lock(&cadet_io_lock);
outb(7,io); /* Select tuner control */
if((inb(io+1)&0x20)!=0) {
cadet_lock--;
return 0xffff;
}
else {
cadet_lock--;
return 0;
}
if((inb(io + 1) & 0x20) != 0)
ret = 0xffff;
spin_unlock(&cadet_io_lock);
return ret;
}
static void cadet_setvol(int vol)
{
cadet_lock++;
spin_lock(&cadet_io_lock);
outb(7,io); /* Select tuner control */
if(vol>0) {
if(vol>0)
outb(0x20,io+1);
}
else {
else
outb(0x00,io+1);
}
cadet_lock--;
spin_unlock(&cadet_io_lock);
}
void cadet_handler(unsigned long data)
{
/*
* Service the RDS fifo
*/
if(cadet_lock==0) {
if(spin_trylock(&cadet_io_lock))
{
outb(0x3,io); /* Select RDS Decoder Control */
if((inb(io+1)&0x20)!=0) {
printk(KERN_CRIT "cadet: RDS fifo overflow\n");
}
outb(0x80,io); /* Select RDS fifo */
while((inb(io)&0x80)!=0) {
rdsbuf[rdsin++]=inb(io+1);
if(rdsin==rdsout) {
printk(KERN_CRIT "cadet: RDS buffer overflow\n");
}
rdsbuf[rdsin]=inb(io+1);
if(rdsin==rdsout)
printk(KERN_WARNING "cadet: RDS buffer overflow\n");
else
rdsin++;
}
spin_unlock(&cadet_io_lock);
}
/*
* Service pending read
*/
if( rdsin!=rdsout) {
if( rdsin!=rdsout)
wake_up_interruptible(&readq);
}
/*
* Clean up and exit
......@@ -359,10 +330,10 @@ static ssize_t cadet_read(struct file *file, char *data,
unsigned char readbuf[RDS_BUFFER];
if(rdsstat==0) {
cadet_lock++;
spin_lock(&cadet_io_lock);
rdsstat=1;
outb(0x80,io); /* Select RDS fifo */
cadet_lock--;
spin_unlock(&cadet_io_lock);
init_timer(&readtimer);
readtimer.function=cadet_handler;
readtimer.data=(unsigned long)0;
......@@ -370,14 +341,13 @@ static ssize_t cadet_read(struct file *file, char *data,
add_timer(&readtimer);
}
if(rdsin==rdsout) {
if (file->f_flags & O_NONBLOCK) {
if (file->f_flags & O_NONBLOCK)
return -EWOULDBLOCK;
}
interruptible_sleep_on(&readq);
}
while((i<count)&&(rdsin!=rdsout)) {
while( i<count && rdsin!=rdsout)
readbuf[i++]=rdsbuf[rdsout++];
}
if (copy_to_user(data,readbuf,i))
return -EFAULT;
return i;
......@@ -515,10 +485,8 @@ static int cadet_open(struct inode *inode, struct file *file)
static int cadet_release(struct inode *inode, struct file *file)
{
if(rdsstat==1) {
del_timer(&readtimer);
del_timer_sync(&readtimer);
rdsstat=0;
}
users--;
return 0;
}
......@@ -595,13 +563,15 @@ static int cadet_probe(void)
return -1;
}
/*
/*
* io should only be set if the user has used something like
* isapnp (the userspace program) to initialize this card for us
*/
static int __init cadet_init(void)
{
spin_lock_init(&cadet_io_lock);
/*
* If a probe was requested then probe ISAPnP first (safest)
*/
......
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