I have an Iomega Z100P2 zip drive, but it does not work with my StarTech
PEX1P2 AX99100 PCIe parallel port, which evidently does not support
16-bit or 32-bit EPP. Currently the only way to tell the PPA driver to
use 8-bit EPP is to write 'mode=3' to /proc/scsi/ppa/*, but the driver
doesn't actually distinguish between the three EPP modes and still tries
to use 16-bit or 32-bit EPP. And even if writing to that file did make
the driver use 8-bit EPP, it still wouldn't do me any good because by
the time that file exists, the drive has already failed to initialize.
Add a new parameter /sys/module/ppa/mode to set the transfer mode before
initializing the drive. This parameter replaces the use of
CONFIG_SCSI_IZIP_EPP16 in the PPA driver.
At the same time, default to 8-bit EPP. 16-bit and 32-bit EPP are not
necessary for the drive to function, nor are they part of the IEEE 1284
standard, so the driver should not assume that they are available.
Signed-off-by: Alex Henrie <alexhenrie24@xxxxxxxxx>
---
drivers/scsi/Kconfig | 2 +-
drivers/scsi/ppa.c | 82 +++++++++++++++++++++++---------------------
drivers/scsi/ppa.h | 4 ---
3 files changed, 43 insertions(+), 45 deletions(-)
diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 4962ce989113..695a57d894cd 100644
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -836,7 +836,7 @@ config SCSI_IMM
config SCSI_IZIP_EPP16
bool "ppa/imm option - Use slow (but safe) EPP-16"
- depends on SCSI_PPA || SCSI_IMM
+ depends on SCSI_IMM
help
EPP (Enhanced Parallel Port) is a standard for parallel ports which
allows them to act as expansion buses that can handle up to 64
diff --git a/drivers/scsi/ppa.c b/drivers/scsi/ppa.c
index d1f6aa256eba..19f0b93fa3d8 100644
--- a/drivers/scsi/ppa.c
+++ b/drivers/scsi/ppa.c
@@ -45,6 +45,11 @@ typedef struct {
#include "ppa.h"
+static unsigned int mode = PPA_AUTODETECT;
+module_param(mode, uint, 0644);
+MODULE_PARM_DESC(mode, "Transfer mode (0 = Autodetect, 1 = SPP 4-bit, "
+ "2 = SPP 8-bit, 3 = EPP 8-bit, 4 = EPP 16-bit, 5 = EPP 32-bit");
+
static struct scsi_pointer *ppa_scsi_pointer(struct scsi_cmnd *cmd)
{
return scsi_cmd_priv(cmd);
@@ -157,7 +162,7 @@ static int ppa_show_info(struct seq_file *m, struct Scsi_Host *host)
return 0;
}
-static int device_check(ppa_struct *dev);
+static int device_check(ppa_struct *dev, bool autodetect);
#if PPA_DEBUG > 0
#define ppa_fail(x,y) printk("ppa: ppa_fail(%i) from %s at line %d\n",\
@@ -302,13 +307,10 @@ static int ppa_out(ppa_struct *dev, char *buffer, int len)
case PPA_EPP_8:
epp_reset(ppb);
w_ctr(ppb, 0x4);
-#ifdef CONFIG_SCSI_IZIP_EPP16
- if (!(((long) buffer | len) & 0x01))
- outsw(ppb + 4, buffer, len >> 1);
-#else
- if (!(((long) buffer | len) & 0x03))
+ if (dev->mode == PPA_EPP_32 && !(((long) buffer | len) & 0x01))
outsl(ppb + 4, buffer, len >> 2);
-#endif
+ else if (dev->mode == PPA_EPP_16 && !(((long) buffer | len) & 0x03))
+ outsw(ppb + 4, buffer, len >> 1);
else
outsb(ppb + 4, buffer, len);
w_ctr(ppb, 0xc);
@@ -355,13 +357,10 @@ static int ppa_in(ppa_struct *dev, char *buffer, int len)
case PPA_EPP_8:
epp_reset(ppb);
w_ctr(ppb, 0x24);
-#ifdef CONFIG_SCSI_IZIP_EPP16
- if (!(((long) buffer | len) & 0x01))
- insw(ppb + 4, buffer, len >> 1);
-#else
- if (!(((long) buffer | len) & 0x03))
+ if (dev->mode == PPA_EPP_32 && !(((long) buffer | len) & 0x03))
insl(ppb + 4, buffer, len >> 2);
-#endif
+ else if (dev->mode == PPA_EPP_16 && !(((long) buffer | len) & 0x01))
+ insw(ppb + 4, buffer, len >> 1);
else
insb(ppb + 4, buffer, len);
w_ctr(ppb, 0x2c);
@@ -469,6 +468,27 @@ static int ppa_init(ppa_struct *dev)
{
int retv;
unsigned short ppb = dev->base;
+ bool autodetect = dev->mode == PPA_AUTODETECT;
+
+ if (autodetect) {
+ int modes = dev->dev->port->modes;
+ int ppb_hi = dev->dev->port->base_hi;
+
+ /* Mode detection works up the chain of speed
+ * This avoids a nasty if-then-else-if-... tree
+ */
+ dev->mode = PPA_NIBBLE;
+
+ if (modes & PARPORT_MODE_TRISTATE)
+ dev->mode = PPA_PS2;
+
+ if (modes & PARPORT_MODE_ECP) {
+ w_ecr(ppb_hi, 0x20);
+ dev->mode = PPA_PS2;
+ }
+ if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
+ w_ecr(ppb_hi, 0x80);
+ }
ppa_disconnect(dev);
ppa_connect(dev, CONNECT_NORMAL);
@@ -492,7 +512,7 @@ static int ppa_init(ppa_struct *dev)
if (retv)
return -EIO;
- return device_check(dev);
+ return device_check(dev, autodetect);
}
static inline int ppa_send_command(struct scsi_cmnd *cmd)
@@ -883,7 +903,7 @@ static int ppa_reset(struct scsi_cmnd *cmd)
return SUCCESS;
}
-static int device_check(ppa_struct *dev)
+static int device_check(ppa_struct *dev, bool autodetect)
{
/* This routine looks for a device and then attempts to use EPP
to send a command. If all goes as planned then EPP is available. */
@@ -895,8 +915,8 @@ static int device_check(ppa_struct *dev)
old_mode = dev->mode;
for (loop = 0; loop < 8; loop++) {
/* Attempt to use EPP for Test Unit Ready */
- if ((ppb & 0x0007) == 0x0000)
- dev->mode = PPA_EPP_32;
+ if (autodetect && (ppb & 0x0007) == 0x0000)
+ dev->mode = PPA_EPP_8;
second_pass:
ppa_connect(dev, CONNECT_EPP_MAYBE);
@@ -924,7 +944,7 @@ static int device_check(ppa_struct *dev)
udelay(1000);
ppa_disconnect(dev);
udelay(1000);
- if (dev->mode == PPA_EPP_32) {
+ if (dev->mode != old_mode) {
dev->mode = old_mode;
goto second_pass;
}
@@ -947,7 +967,7 @@ static int device_check(ppa_struct *dev)
udelay(1000);
ppa_disconnect(dev);
udelay(1000);
- if (dev->mode == PPA_EPP_32) {
+ if (dev->mode != old_mode) {
dev->mode = old_mode;
goto second_pass;
}
@@ -1026,7 +1046,6 @@ static int __ppa_attach(struct parport *pb)
DEFINE_WAIT(wait);
ppa_struct *dev, *temp;
int ports;
- int modes, ppb, ppb_hi;
int err = -ENOMEM;
struct pardev_cb ppa_cb;
@@ -1034,7 +1053,7 @@ static int __ppa_attach(struct parport *pb)
if (!dev)
return -ENOMEM;
dev->base = -1;
- dev->mode = PPA_AUTODETECT;
+ dev->mode = mode < PPA_UNKNOWN ? mode : PPA_AUTODETECT;
dev->recon_tmo = PPA_RECON_TMO;
init_waitqueue_head(&waiting);
temp = find_parent();
@@ -1069,25 +1088,8 @@ static int __ppa_attach(struct parport *pb)
}
dev->waiting = NULL;
finish_wait(&waiting, &wait);
- ppb = dev->base = dev->dev->port->base;
- ppb_hi = dev->dev->port->base_hi;
- w_ctr(ppb, 0x0c);
- modes = dev->dev->port->modes;
-
- /* Mode detection works up the chain of speed
- * This avoids a nasty if-then-else-if-... tree
- */
- dev->mode = PPA_NIBBLE;
-
- if (modes & PARPORT_MODE_TRISTATE)
- dev->mode = PPA_PS2;
-
- if (modes & PARPORT_MODE_ECP) {
- w_ecr(ppb_hi, 0x20);
- dev->mode = PPA_PS2;
- }
- if ((modes & PARPORT_MODE_EPP) && (modes & PARPORT_MODE_ECP))
- w_ecr(ppb_hi, 0x80);
+ dev->base = dev->dev->port->base;
+ w_ctr(dev->base, 0x0c);
/* Done configuration */
diff --git a/drivers/scsi/ppa.h b/drivers/scsi/ppa.h
index 6a1f8a2d70eb..098bcf7b9eb4 100644
--- a/drivers/scsi/ppa.h
+++ b/drivers/scsi/ppa.h
@@ -107,11 +107,7 @@ static char *PPA_MODE_STRING[] =
"PS/2",
"EPP 8 bit",
"EPP 16 bit",
-#ifdef CONFIG_SCSI_IZIP_EPP16
- "EPP 16 bit",
-#else
"EPP 32 bit",
-#endif
"Unknown"};
/* other options */
--
2.41.0
