scsi: imm: Add a module parameter for the transfer mode

Fix in the imm driver the same problem that was fixed in the ppa driver by
commit 68a4f84a17c1 ("scsi: ppa: Add a module parameter for the transfer
mode").

Tested and confirmed working with an Iomega Z250P zip drive and a StarTech
PEX1P2 AX99100 PCIe parallel port.

Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Link: https://lore.kernel.org/r/20230831054620.515611-1-alexhenrie24@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
index 695a57d894cdd0cba13bd1462ca7f2bf4a368b9a..addac7fbe37b9870380cc715acf923344071e6e6 100644 (file)
--- a/drivers/scsi/Kconfig
+++ b/drivers/scsi/Kconfig
@@ -834,21 +834,6 @@ config SCSI_IMM
          To compile this driver as a module, choose M here: the
          module will be called imm.
 
-config SCSI_IZIP_EPP16
-       bool "ppa/imm option - Use slow (but safe) EPP-16"
-       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
-         peripheral devices.
-
-         Some parallel port chipsets are slower than their motherboard, and
-         so we have to control the state of the chipset's FIFO queue every
-         now and then to avoid data loss. This will be done if you say Y
-         here.
-
-         Generally, saying Y is the safe option and slows things down a bit.
-
 config SCSI_IZIP_SLOW_CTR
        bool "ppa/imm option - Assume slow parport control register"
        depends on SCSI_PPA || SCSI_IMM

diff --git a/drivers/scsi/imm.c b/drivers/scsi/imm.c
index 07db98161a0365e0158d7a29b9e4f96e4aed2440..180a5ddedb2cdaa0c9f57050618707ed97045337 100644 (file)
--- a/drivers/scsi/imm.c
+++ b/drivers/scsi/imm.c
@@ -51,10 +51,15 @@ typedef struct {
 } imm_struct;
 
 static void imm_reset_pulse(unsigned int base);
-static int device_check(imm_struct *dev);
+static int device_check(imm_struct *dev, bool autodetect);
 
 #include "imm.h"
 
+static unsigned int mode = IMM_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 inline imm_struct *imm_dev(struct Scsi_Host *host)
 {
        return *(imm_struct **)&host->hostdata;
@@ -366,13 +371,10 @@ static int imm_out(imm_struct *dev, char *buffer, int len)
        case IMM_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 == IMM_EPP_32 && !(((long) buffer | len) & 0x03))
                        outsl(ppb + 4, buffer, len >> 2);
-#endif
+               else if (dev->mode == IMM_EPP_16 && !(((long) buffer | len) & 0x01))
+                       outsw(ppb + 4, buffer, len >> 1);
                else
                        outsb(ppb + 4, buffer, len);
                w_ctr(ppb, 0xc);
@@ -426,13 +428,10 @@ static int imm_in(imm_struct *dev, char *buffer, int len)
        case IMM_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))
-                       insl(ppb + 4, buffer, len >> 2);
-#endif
+               if (dev->mode == IMM_EPP_32 && !(((long) buffer | len) & 0x03))
+                       insw(ppb + 4, buffer, len >> 2);
+               else if (dev->mode == IMM_EPP_16 && !(((long) buffer | len) & 0x01))
+                       insl(ppb + 4, buffer, len >> 1);
                else
                        insb(ppb + 4, buffer, len);
                w_ctr(ppb, 0x2c);
@@ -589,13 +588,28 @@ static int imm_select(imm_struct *dev, int target)
 
 static int imm_init(imm_struct *dev)
 {
+       bool autodetect = dev->mode == IMM_AUTODETECT;
+
+       if (autodetect) {
+               int modes = dev->dev->port->modes;
+
+               /* Mode detection works up the chain of speed
+                * This avoids a nasty if-then-else-if-... tree
+                */
+               dev->mode = IMM_NIBBLE;
+
+               if (modes & PARPORT_MODE_TRISTATE)
+                       dev->mode = IMM_PS2;
+       }
+
        if (imm_connect(dev, 0) != 1)
                return -EIO;
        imm_reset_pulse(dev->base);
        mdelay(1);      /* Delay to allow devices to settle */
        imm_disconnect(dev);
        mdelay(1);      /* Another delay to allow devices to settle */
-       return device_check(dev);
+
+       return device_check(dev, autodetect);
 }
 
 static inline int imm_send_command(struct scsi_cmnd *cmd)
@@ -1000,7 +1014,7 @@ static int imm_reset(struct scsi_cmnd *cmd)
        return SUCCESS;
 }
 
-static int device_check(imm_struct *dev)
+static int device_check(imm_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. */
@@ -1012,8 +1026,8 @@ static int device_check(imm_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 = IMM_EPP_32;
+               if (autodetect && (ppb & 0x0007) == 0x0000)
+                       dev->mode = IMM_EPP_8;
 
              second_pass:
                imm_connect(dev, CONNECT_EPP_MAYBE);
@@ -1038,7 +1052,7 @@ static int device_check(imm_struct *dev)
                        udelay(1000);
                        imm_disconnect(dev);
                        udelay(1000);
-                       if (dev->mode == IMM_EPP_32) {
+                       if (dev->mode != old_mode) {
                                dev->mode = old_mode;
                                goto second_pass;
                        }
@@ -1063,7 +1077,7 @@ static int device_check(imm_struct *dev)
                        udelay(1000);
                        imm_disconnect(dev);
                        udelay(1000);
-                       if (dev->mode == IMM_EPP_32) {
+                       if (dev->mode != old_mode) {
                                dev->mode = old_mode;
                                goto second_pass;
                        }
@@ -1150,7 +1164,6 @@ static int __imm_attach(struct parport *pb)
        DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
        DEFINE_WAIT(wait);
        int ports;
-       int modes, ppb;
        int err = -ENOMEM;
        struct pardev_cb imm_cb;
 
@@ -1162,7 +1175,7 @@ static int __imm_attach(struct parport *pb)
 
 
        dev->base = -1;
-       dev->mode = IMM_AUTODETECT;
+       dev->mode = mode < IMM_UNKNOWN ? mode : IMM_AUTODETECT;
        INIT_LIST_HEAD(&dev->list);
 
        temp = find_parent();
@@ -1197,18 +1210,9 @@ static int __imm_attach(struct parport *pb)
        }
        dev->waiting = NULL;
        finish_wait(&waiting, &wait);
-       ppb = dev->base = dev->dev->port->base;
+       dev->base = dev->dev->port->base;
        dev->base_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 = IMM_NIBBLE;
-
-       if (modes & PARPORT_MODE_TRISTATE)
-               dev->mode = IMM_PS2;
+       w_ctr(dev->base, 0x0c);
 
        /* Done configuration */
 

diff --git a/drivers/scsi/imm.h b/drivers/scsi/imm.h
index 411cf94af5b000c39a232ca661af808ba3ea3110..398fa5b15181ce9862b980bc76b86bb0ee8a2d37 100644 (file)
--- a/drivers/scsi/imm.h
+++ b/drivers/scsi/imm.h
@@ -100,11 +100,7 @@ static char *IMM_MODE_STRING[] =
        [IMM_PS2]        = "PS/2",
        [IMM_EPP_8]      = "EPP 8 bit",
        [IMM_EPP_16]     = "EPP 16 bit",
-#ifdef CONFIG_SCSI_IZIP_EPP16
-       [IMM_EPP_32]     = "EPP 16 bit",
-#else
        [IMM_EPP_32]     = "EPP 32 bit",
-#endif
        [IMM_UNKNOWN]    = "Unknown",
 };