--- libata-dev-2.6-reorg/drivers/scsi/pata_pdc2027x.c	2005-04-11 15:05:28.000000000 +0800
+++ libata-dev-2.6-pll-fix/drivers/scsi/pata_pdc2027x.c	2005-04-11 15:05:42.000000000 +0800
@@ -29,7 +29,7 @@
 #include <asm/io.h>
 
 #define DRV_NAME	"pata_pdc2027x"
-#define DRV_VERSION	"0.59"
+#define DRV_VERSION	"0.60"
 #undef PDC_DEBUG
 
 #ifdef PDC_DEBUG
@@ -463,7 +463,10 @@
 {
 	u8 ctr0, ctr1, ctr2, ctr3;
 	unsigned long counter;
+	u8 ctr0v, ctr1v, ctr2v, ctr3v;
+	int retry = 1;
 
+retry:
 	outb(0x20, probe_ent->port[0].bmdma_addr + 0x01);
 	ctr0 = inb(probe_ent->port[0].bmdma_addr + 0x03);
 	outb(0x21, probe_ent->port[0].bmdma_addr + 0x01);
@@ -473,10 +476,32 @@
 	outb(0x21, probe_ent->port[1].bmdma_addr + 0x01);
 	ctr3 = inb(probe_ent->port[1].bmdma_addr + 0x03);
 
+	/* Read the counter values again for verification */
+	outb(0x20,  probe_ent->port[0].bmdma_addr + 0x01);
+	ctr0v = inb(probe_ent->port[0].bmdma_addr + 0x03);
+	outb(0x21,  probe_ent->port[0].bmdma_addr + 0x01);
+	ctr1v = inb(probe_ent->port[0].bmdma_addr + 0x03);
+	outb(0x20,  probe_ent->port[1].bmdma_addr + 0x01);
+	ctr2v = inb(probe_ent->port[1].bmdma_addr + 0x03);
+	outb(0x21,  probe_ent->port[1].bmdma_addr + 0x01);
+	ctr3v = inb(probe_ent->port[1].bmdma_addr + 0x03);
+
 	counter = (ctr3 << 23) | (ctr2 << 15) | (ctr1 << 8) | ctr0;
 
 	PDPRINTK("ctr0[%X] ctr1[%X] ctr2[%X] ctr3[%X]\n", 
 		 ctr0, ctr1, ctr2, ctr3);
+	PDPRINTK("ctr0[%X] ctr1[%X] ctr2[%X] ctr3[%X]\n", 
+		 ctr0v, ctr1v, ctr2v, ctr3v);
+
+	/*
+	 * The 30-bit decreasing counter are read by 4 pieces.
+	 * Incorrect value may be read when ctr2 and ctr3 are changing.
+	 */
+	if (retry && !(ctr3 == ctr3v && ctr2 == ctr2v && ctr1 >= ctr1v)) {
+		retry--;
+		PDPRINTK("rereading counter\n");
+		goto retry;
+	}
 
 	return counter;
 }
@@ -599,8 +624,8 @@
 	PDPRINTK("scr1[%X]\n", scr1);
 	outb(scr1 | 0x40, probe_ent->port[0].bmdma_addr + 0x03);
 
-	/* Let the counter run for 1000 us. */
-	udelay(1000);
+	/* Let the counter run for 100 ms. */
+	mdelay(100);
 
 	/* Read the counter values again */
 	end_count = pdc_read_counter(probe_ent);
@@ -612,7 +637,7 @@
 	outb(scr1 & 0xBF, probe_ent->port[0].bmdma_addr + 0x03);
 
 	/* calculate the input clock in Hz */
-	pll_clock = (long) ((start_count - end_count) * 1000);
+	pll_clock = (long) ((start_count - end_count) * 10);
 
 	PDPRINTK("start[%lu] end[%lu] \n", start_count, end_count);
 	PDPRINTK("PLL input clock[%ld]Hz\n", pll_clock);