--Ken Pizzini
--- linux-2.1.127-pre7+sfrost/drivers/cdrom/sonycd535.c Thu Nov 5 07:58:47 1998
+++ linux/drivers/cdrom/sonycd535.c Thu Nov 5 17:55:15 1998
@@ -62,26 +62,24 @@
* This interface is (unfortunately) a polled interface. This is
* because most Sony interfaces are set up with DMA and interrupts
* disables. Some (like mine) do not even have the capability to
- * handle interrupts or DMA. For this reason you will see a lot of
+ * handle interrupts or DMA. For this reason you will see a bit of
* the following:
*
- * retry_count = jiffies+ SONY_JIFFIES_TIMEOUT;
- * while ((retry_count > jiffies) && (! <some condition to wait for))
+ * snap = jiffies;
+ * while (jiffies-snap < SONY_JIFFIES_TIMEOUT)
* {
- * while (handle_sony_cd_attention())
- * ;
- *
+ * if (some_condition())
+ * break;
* sony_sleep();
* }
- * if (the condition not met)
+ * if (some_condition not met)
* {
- * return an error;
+ * return an_error;
* }
*
* This ugly hack waits for something to happen, sleeping a little
- * between every try. it also handles attentions, which are
- * asynchronous events from the drive informing the driver that a disk
- * has been inserted, removed, etc.
+ * between every try. (The conditional is written so that jiffies
+ * wrap-around is handled properly.)
*
* One thing about these drives: They talk in MSF (Minute Second Frame) format.
* There are 75 frames a second, 60 seconds a minute, and up to 75 minutes on a
@@ -327,9 +325,7 @@
/*
- * Wait a little while (used for polling the drive). If in initialization,
- * setting a timeout doesn't work, so just loop for a while. (We trust
- * that the sony_sleep() call is protected by a test for proper jiffies count.)
+ * Wait a little while.
*/
static inline void
sony_sleep(void)
@@ -369,12 +365,13 @@
static int
read_result_reg(Byte *data_ptr)
{
- int retry_count;
+ unsigned long snap;
int read_status;
- retry_count = jiffies + SONY_JIFFIES_TIMEOUT;
- while (jiffies < retry_count) {
- if (((read_status = inb(read_status_reg)) & SONY535_RESULT_NOT_READY_BIT) == 0) {
+ snap = jiffies;
+ while (jiffies-snap < SONY_JIFFIES_TIMEOUT) {
+ read_status = inb(read_status_reg);
+ if ((read_status & SONY535_RESULT_NOT_READY_BIT) == 0) {
#if DEBUG > 1
printk(CDU535_MESSAGE_NAME
": read_result_reg(): readStatReg = 0x%x\n", read_status);
@@ -598,7 +595,7 @@
Byte cmd_buff[7];
int i;
int read_status;
- int retry_count;
+ unsigned long snap;
Byte *data_buff;
int sector_count = 0;
@@ -617,8 +614,9 @@
/* read back the data one block at a time */
while (0 < n_blocks--) {
/* wait for data to be ready */
- retry_count = jiffies + SONY_JIFFIES_TIMEOUT;
- while (jiffies < retry_count) {
+ int data_valid = 0;
+ snap = jiffies;
+ while (jiffies-snap < SONY_JIFFIES_TIMEOUT) {
read_status = inb(read_status_reg);
if ((read_status & SONY535_RESULT_NOT_READY_BIT) == 0) {
read_exec_status(status);
@@ -629,11 +627,12 @@
data_buff = buff[sector_count++];
for (i = 0; i < block_size; i++)
*data_buff++ = inb(data_reg); /* unrolling this loop does not seem to help */
+ data_valid = 1;
break; /* exit the timeout loop */
}
sony_sleep(); /* data not ready, sleep a while */
}
- if (retry_count <= jiffies)
+ if (!data_valid)
return TIME_OUT; /* if we reach this stage */
}
@@ -892,7 +891,7 @@
if (readStatus == BAD_STATUS) {
/* Sleep for a while, then retry */
current->state = TASK_INTERRUPTIBLE;
- schedule_timeout(RETRY_FOR_BAD_STATUS);
+ schedule_timeout(RETRY_FOR_BAD_STATUS*HZ/10);
}
#if DEBUG > 0
printk(CDU535_MESSAGE_NAME
@@ -1491,7 +1490,8 @@
Byte cmd_buff[3];
Byte ret_buff[2];
Byte status[2];
- int retry_count;
+ unsigned long snap;
+ int got_result = 0;
int tmp_irq;
int i;
@@ -1523,21 +1523,22 @@
}
/* look for the CD-ROM, follows the procedure in the DOS driver */
inb(select_unit_reg);
- retry_count = jiffies + 2 * HZ;
- while (jiffies < retry_count)
- sony_sleep(); /* wait for 40 18 Hz ticks (from DOS driver) */
+ /* wait for 40 18 Hz ticks (reverse-engineered from DOS driver) */
+ schedule_timeout((HZ+17)*40/18);
inb(result_reg);
outb(0, read_status_reg); /* does a reset? */
- retry_count = jiffies + SONY_JIFFIES_TIMEOUT;
- while (jiffies < retry_count) {
+ snap = jiffies;
+ while (jiffies-snap < SONY_JIFFIES_TIMEOUT) {
select_unit(0);
- if (inb(result_reg) != 0xff)
+ if (inb(result_reg) != 0xff) {
+ got_result = 1;
break;
+ }
sony_sleep();
}
- if ((jiffies < retry_count) && (check_drive_status() != TIME_OUT)) {
+ if (got_result && (check_drive_status() != TIME_OUT)) {
/* CD-ROM drive responded -- get the drive configuration */
cmd_buff[0] = SONY535_INQUIRY;
if (do_sony_cmd(cmd_buff, 1, status,
-
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