From 68a4f84a17c1d83daf8c07446ca32f7958f49c04 Mon Sep 17 00:00:00 2001 From: Alex Henrie Date: Mon, 7 Aug 2023 09:52:58 -0600 Subject: [PATCH] scsi: ppa: Add a module parameter for the transfer mode 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 Link: https://lore.kernel.org/r/20230807155856.362864-2-alexhenrie24@gmail.com Signed-off-by: Martin K. Petersen --- 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 @@ second_pass: 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 @@ second_pass: 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 */