[SCSI] mac_esp: fix PIO mode, take 2
The mac_esp PIO algorithm no longer works in 2.6.31 and crashes my Centris
660av. So here's a better one.
Also, force async with esp_set_offset() rather than esp_slave_configure().
One of the SCSI drives I tested still doesn't like the PIO mode and fails
with "esp: esp0: Reconnect IRQ2 timeout" (the same drive works fine in
PDMA mode).
This failure happens when esp_reconnect_with_tag() tries to read in two
tag bytes but the chip only provides one (0x20). I don't know what causes
this. I decided not to waste any more time trying to fix it because the
best solution is to rip out the PIO mode altogether and use the DMA
engine.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/mac_esp.c b/drivers/scsi/mac_esp.c
index c24e86f..dd808ae 100644
--- a/drivers/scsi/mac_esp.c
+++ b/drivers/scsi/mac_esp.c
@@ -22,7 +22,6 @@
#include <asm/irq.h>
#include <asm/dma.h>
-
#include <asm/macints.h>
#include <asm/macintosh.h>
@@ -279,24 +278,27 @@
* Programmed IO routines follow.
*/
-static inline int mac_esp_wait_for_fifo(struct esp *esp)
+static inline unsigned int mac_esp_wait_for_fifo(struct esp *esp)
{
int i = 500000;
do {
- if (esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES)
- return 0;
+ unsigned int fbytes = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
+
+ if (fbytes)
+ return fbytes;
udelay(2);
} while (--i);
printk(KERN_ERR PFX "FIFO is empty (sreg %02x)\n",
esp_read8(ESP_STATUS));
- return 1;
+ return 0;
}
static inline int mac_esp_wait_for_intr(struct esp *esp)
{
+ struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
int i = 500000;
do {
@@ -308,6 +310,7 @@
} while (--i);
printk(KERN_ERR PFX "IRQ timeout (sreg %02x)\n", esp->sreg);
+ mep->error = 1;
return 1;
}
@@ -347,11 +350,10 @@
static void mac_esp_send_pio_cmd(struct esp *esp, u32 addr, u32 esp_count,
u32 dma_count, int write, u8 cmd)
{
- unsigned long flags;
struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);
u8 *fifo = esp->regs + ESP_FDATA * 16;
- local_irq_save(flags);
+ disable_irq(esp->host->irq);
cmd &= ~ESP_CMD_DMA;
mep->error = 0;
@@ -359,11 +361,35 @@
if (write) {
scsi_esp_cmd(esp, cmd);
- if (!mac_esp_wait_for_intr(esp)) {
- if (mac_esp_wait_for_fifo(esp))
- esp_count = 0;
- } else {
- esp_count = 0;
+ while (1) {
+ unsigned int n;
+
+ n = mac_esp_wait_for_fifo(esp);
+ if (!n)
+ break;
+
+ if (n > esp_count)
+ n = esp_count;
+ esp_count -= n;
+
+ MAC_ESP_PIO_LOOP("%2@,%0@+", n);
+
+ if (!esp_count)
+ break;
+
+ if (mac_esp_wait_for_intr(esp))
+ break;
+
+ if (((esp->sreg & ESP_STAT_PMASK) != ESP_DIP) &&
+ ((esp->sreg & ESP_STAT_PMASK) != ESP_MIP))
+ break;
+
+ esp->ireg = esp_read8(ESP_INTRPT);
+ if ((esp->ireg & (ESP_INTR_DC | ESP_INTR_BSERV)) !=
+ ESP_INTR_BSERV)
+ break;
+
+ scsi_esp_cmd(esp, ESP_CMD_TI);
}
} else {
scsi_esp_cmd(esp, ESP_CMD_FLUSH);
@@ -374,47 +400,24 @@
MAC_ESP_PIO_LOOP("%0@+,%2@", esp_count);
scsi_esp_cmd(esp, cmd);
- }
- while (esp_count) {
- unsigned int n;
+ while (esp_count) {
+ unsigned int n;
- if (mac_esp_wait_for_intr(esp)) {
- mep->error = 1;
- break;
- }
-
- if (esp->sreg & ESP_STAT_SPAM) {
- printk(KERN_ERR PFX "gross error\n");
- mep->error = 1;
- break;
- }
-
- n = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
-
- if (write) {
- if (n > esp_count)
- n = esp_count;
- esp_count -= n;
-
- MAC_ESP_PIO_LOOP("%2@,%0@+", n);
-
- if ((esp->sreg & ESP_STAT_PMASK) == ESP_STATP)
+ if (mac_esp_wait_for_intr(esp))
break;
- if (esp_count) {
- esp->ireg = esp_read8(ESP_INTRPT);
- if (esp->ireg & ESP_INTR_DC)
- break;
+ if (((esp->sreg & ESP_STAT_PMASK) != ESP_DOP) &&
+ ((esp->sreg & ESP_STAT_PMASK) != ESP_MOP))
+ break;
- scsi_esp_cmd(esp, ESP_CMD_TI);
- }
- } else {
esp->ireg = esp_read8(ESP_INTRPT);
- if (esp->ireg & ESP_INTR_DC)
+ if ((esp->ireg & (ESP_INTR_DC | ESP_INTR_BSERV)) !=
+ ESP_INTR_BSERV)
break;
- n = MAC_ESP_FIFO_SIZE - n;
+ n = MAC_ESP_FIFO_SIZE -
+ (esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES);
if (n > esp_count)
n = esp_count;
@@ -429,7 +432,7 @@
}
}
- local_irq_restore(flags);
+ enable_irq(esp->host->irq);
}
static int mac_esp_irq_pending(struct esp *esp)