From 7398cee4c3e6aea1ba07a6449e5533ecd0b92cdd Mon Sep 17 00:00:00 2001 From: Finn Thain Date: Sun, 9 Jun 2019 11:19:11 +1000 Subject: scsi: mac_scsi: Increase PIO/PDMA transfer length threshold Some targets introduce delays when handshaking the response to certain commands. For example, a disk may send a 96-byte response to an INQUIRY command (or a 24-byte response to a MODE SENSE command) too slowly. Apparently the first 12 or 14 bytes are handshaked okay but then the system bus error timeout is reached while transferring the next word. Since the scsi bus phase hasn't changed, the driver then sets the target borken flag to prevent further PDMA transfers. The driver also logs the warning, "switching to slow handshake". Raise the PDMA threshold to 512 bytes so that PIO transfers will be used for these commands. This default is sufficiently low that PDMA will still be used for READ and WRITE commands. The existing threshold (16 bytes) was chosen more or less at random. However, best performance requires the threshold to be as low as possible. Those systems that don't need the PIO workaround at all may benefit from mac_scsi.setup_use_pdma=1 Cc: Michael Schmitz Cc: stable@vger.kernel.org # v4.14+ Fixes: 3a0f64bfa907 ("mac_scsi: Fix pseudo DMA implementation") Signed-off-by: Finn Thain Tested-by: Stan Johnson Tested-by: Michael Schmitz Signed-off-by: Martin K. Petersen --- drivers/scsi/mac_scsi.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/scsi/mac_scsi.c') diff --git a/drivers/scsi/mac_scsi.c b/drivers/scsi/mac_scsi.c index 8b4b5b1a13d7..ba1afcaadae8 100644 --- a/drivers/scsi/mac_scsi.c +++ b/drivers/scsi/mac_scsi.c @@ -52,7 +52,7 @@ static int setup_cmd_per_lun = -1; module_param(setup_cmd_per_lun, int, 0); static int setup_sg_tablesize = -1; module_param(setup_sg_tablesize, int, 0); -static int setup_use_pdma = -1; +static int setup_use_pdma = 512; module_param(setup_use_pdma, int, 0); static int setup_hostid = -1; module_param(setup_hostid, int, 0); @@ -305,7 +305,7 @@ static int macscsi_dma_xfer_len(struct NCR5380_hostdata *hostdata, struct scsi_cmnd *cmd) { if (hostdata->flags & FLAG_NO_PSEUDO_DMA || - cmd->SCp.this_residual < 16) + cmd->SCp.this_residual < setup_use_pdma) return 0; return cmd->SCp.this_residual; -- cgit v1.2.3 From 78ff751f8e6a9446e9fb26b2bff0b8d3f8974cbd Mon Sep 17 00:00:00 2001 From: Finn Thain Date: Sun, 9 Jun 2019 11:19:11 +1000 Subject: scsi: mac_scsi: Fix pseudo DMA implementation, take 2 A system bus error during a PDMA transfer can mess up the calculation of the transfer residual (the PDMA handshaking hardware lacks a byte counter). This results in data corruption. The algorithm in this patch anticipates a bus error by starting each transfer with a MOVE.B instruction. If a bus error is caught the transfer will be retried. If a bus error is caught later in the transfer (for a MOVE.W instruction) the transfer gets failed and subsequent requests for that target will use PIO instead of PDMA. This avoids the "!REQ and !ACK" error so the severity level of that message is reduced to KERN_DEBUG. Cc: Michael Schmitz Cc: Geert Uytterhoeven Cc: stable@vger.kernel.org # v4.14+ Fixes: 3a0f64bfa907 ("mac_scsi: Fix pseudo DMA implementation") Signed-off-by: Finn Thain Reported-by: Chris Jones Tested-by: Stan Johnson Tested-by: Michael Schmitz Signed-off-by: Martin K. Petersen --- drivers/scsi/mac_scsi.c | 371 ++++++++++++++++++++++++++++-------------------- 1 file changed, 218 insertions(+), 153 deletions(-) (limited to 'drivers/scsi/mac_scsi.c') diff --git a/drivers/scsi/mac_scsi.c b/drivers/scsi/mac_scsi.c index ba1afcaadae8..27364b71e833 100644 --- a/drivers/scsi/mac_scsi.c +++ b/drivers/scsi/mac_scsi.c @@ -3,6 +3,8 @@ * * Copyright 1998, Michael Schmitz * + * Copyright 2019 Finn Thain + * * derived in part from: */ /* @@ -11,6 +13,7 @@ * Copyright 1995, Russell King */ +#include #include #include #include @@ -89,101 +92,217 @@ static int __init mac_scsi_setup(char *str) __setup("mac5380=", mac_scsi_setup); #endif /* !MODULE */ -/* Pseudo DMA asm originally by Ove Edlund */ - -#define CP_IO_TO_MEM(s,d,n) \ -__asm__ __volatile__ \ - (" cmp.w #4,%2\n" \ - " bls 8f\n" \ - " move.w %1,%%d0\n" \ - " neg.b %%d0\n" \ - " and.w #3,%%d0\n" \ - " sub.w %%d0,%2\n" \ - " bra 2f\n" \ - " 1: move.b (%0),(%1)+\n" \ - " 2: dbf %%d0,1b\n" \ - " move.w %2,%%d0\n" \ - " lsr.w #5,%%d0\n" \ - " bra 4f\n" \ - " 3: move.l (%0),(%1)+\n" \ - "31: move.l (%0),(%1)+\n" \ - "32: move.l (%0),(%1)+\n" \ - "33: move.l (%0),(%1)+\n" \ - "34: move.l (%0),(%1)+\n" \ - "35: move.l (%0),(%1)+\n" \ - "36: move.l (%0),(%1)+\n" \ - "37: move.l (%0),(%1)+\n" \ - " 4: dbf %%d0,3b\n" \ - " move.w %2,%%d0\n" \ - " lsr.w #2,%%d0\n" \ - " and.w #7,%%d0\n" \ - " bra 6f\n" \ - " 5: move.l (%0),(%1)+\n" \ - " 6: dbf %%d0,5b\n" \ - " and.w #3,%2\n" \ - " bra 8f\n" \ - " 7: move.b (%0),(%1)+\n" \ - " 8: dbf %2,7b\n" \ - " moveq.l #0, %2\n" \ - " 9: \n" \ - ".section .fixup,\"ax\"\n" \ - " .even\n" \ - "91: moveq.l #1, %2\n" \ - " jra 9b\n" \ - "94: moveq.l #4, %2\n" \ - " jra 9b\n" \ - ".previous\n" \ - ".section __ex_table,\"a\"\n" \ - " .align 4\n" \ - " .long 1b,91b\n" \ - " .long 3b,94b\n" \ - " .long 31b,94b\n" \ - " .long 32b,94b\n" \ - " .long 33b,94b\n" \ - " .long 34b,94b\n" \ - " .long 35b,94b\n" \ - " .long 36b,94b\n" \ - " .long 37b,94b\n" \ - " .long 5b,94b\n" \ - " .long 7b,91b\n" \ - ".previous" \ - : "=a"(s), "=a"(d), "=d"(n) \ - : "0"(s), "1"(d), "2"(n) \ - : "d0") +/* + * According to "Inside Macintosh: Devices", Mac OS requires disk drivers to + * specify the number of bytes between the delays expected from a SCSI target. + * This allows the operating system to "prevent bus errors when a target fails + * to deliver the next byte within the processor bus error timeout period." + * Linux SCSI drivers lack knowledge of the timing behaviour of SCSI targets + * so bus errors are unavoidable. + * + * If a MOVE.B instruction faults, we assume that zero bytes were transferred + * and simply retry. That assumption probably depends on target behaviour but + * seems to hold up okay. The NOP provides synchronization: without it the + * fault can sometimes occur after the program counter has moved past the + * offending instruction. Post-increment addressing can't be used. + */ + +#define MOVE_BYTE(operands) \ + asm volatile ( \ + "1: moveb " operands " \n" \ + "11: nop \n" \ + " addq #1,%0 \n" \ + " subq #1,%1 \n" \ + "40: \n" \ + " \n" \ + ".section .fixup,\"ax\" \n" \ + ".even \n" \ + "90: movel #1, %2 \n" \ + " jra 40b \n" \ + ".previous \n" \ + " \n" \ + ".section __ex_table,\"a\" \n" \ + ".align 4 \n" \ + ".long 1b,90b \n" \ + ".long 11b,90b \n" \ + ".previous \n" \ + : "+a" (addr), "+r" (n), "+r" (result) : "a" (io)) + +/* + * If a MOVE.W (or MOVE.L) instruction faults, it cannot be retried because + * the residual byte count would be uncertain. In that situation the MOVE_WORD + * macro clears n in the fixup section to abort the transfer. + */ + +#define MOVE_WORD(operands) \ + asm volatile ( \ + "1: movew " operands " \n" \ + "11: nop \n" \ + " subq #2,%1 \n" \ + "40: \n" \ + " \n" \ + ".section .fixup,\"ax\" \n" \ + ".even \n" \ + "90: movel #0, %1 \n" \ + " movel #2, %2 \n" \ + " jra 40b \n" \ + ".previous \n" \ + " \n" \ + ".section __ex_table,\"a\" \n" \ + ".align 4 \n" \ + ".long 1b,90b \n" \ + ".long 11b,90b \n" \ + ".previous \n" \ + : "+a" (addr), "+r" (n), "+r" (result) : "a" (io)) + +#define MOVE_16_WORDS(operands) \ + asm volatile ( \ + "1: movew " operands " \n" \ + "2: movew " operands " \n" \ + "3: movew " operands " \n" \ + "4: movew " operands " \n" \ + "5: movew " operands " \n" \ + "6: movew " operands " \n" \ + "7: movew " operands " \n" \ + "8: movew " operands " \n" \ + "9: movew " operands " \n" \ + "10: movew " operands " \n" \ + "11: movew " operands " \n" \ + "12: movew " operands " \n" \ + "13: movew " operands " \n" \ + "14: movew " operands " \n" \ + "15: movew " operands " \n" \ + "16: movew " operands " \n" \ + "17: nop \n" \ + " subl #32,%1 \n" \ + "40: \n" \ + " \n" \ + ".section .fixup,\"ax\" \n" \ + ".even \n" \ + "90: movel #0, %1 \n" \ + " movel #2, %2 \n" \ + " jra 40b \n" \ + ".previous \n" \ + " \n" \ + ".section __ex_table,\"a\" \n" \ + ".align 4 \n" \ + ".long 1b,90b \n" \ + ".long 2b,90b \n" \ + ".long 3b,90b \n" \ + ".long 4b,90b \n" \ + ".long 5b,90b \n" \ + ".long 6b,90b \n" \ + ".long 7b,90b \n" \ + ".long 8b,90b \n" \ + ".long 9b,90b \n" \ + ".long 10b,90b \n" \ + ".long 11b,90b \n" \ + ".long 12b,90b \n" \ + ".long 13b,90b \n" \ + ".long 14b,90b \n" \ + ".long 15b,90b \n" \ + ".long 16b,90b \n" \ + ".long 17b,90b \n" \ + ".previous \n" \ + : "+a" (addr), "+r" (n), "+r" (result) : "a" (io)) + +#define MAC_PDMA_DELAY 32 + +static inline int mac_pdma_recv(void __iomem *io, unsigned char *start, int n) +{ + unsigned char *addr = start; + int result = 0; + + if (n >= 1) { + MOVE_BYTE("%3@,%0@"); + if (result) + goto out; + } + if (n >= 1 && ((unsigned long)addr & 1)) { + MOVE_BYTE("%3@,%0@"); + if (result) + goto out; + } + while (n >= 32) + MOVE_16_WORDS("%3@,%0@+"); + while (n >= 2) + MOVE_WORD("%3@,%0@+"); + if (result) + return start - addr; /* Negated to indicate uncertain length */ + if (n == 1) + MOVE_BYTE("%3@,%0@"); +out: + return addr - start; +} + +static inline int mac_pdma_send(unsigned char *start, void __iomem *io, int n) +{ + unsigned char *addr = start; + int result = 0; + + if (n >= 1) { + MOVE_BYTE("%0@,%3@"); + if (result) + goto out; + } + if (n >= 1 && ((unsigned long)addr & 1)) { + MOVE_BYTE("%0@,%3@"); + if (result) + goto out; + } + while (n >= 32) + MOVE_16_WORDS("%0@+,%3@"); + while (n >= 2) + MOVE_WORD("%0@+,%3@"); + if (result) + return start - addr; /* Negated to indicate uncertain length */ + if (n == 1) + MOVE_BYTE("%0@,%3@"); +out: + return addr - start; +} static inline int macscsi_pread(struct NCR5380_hostdata *hostdata, unsigned char *dst, int len) { u8 __iomem *s = hostdata->pdma_io + (INPUT_DATA_REG << 4); unsigned char *d = dst; - int n = len; - int transferred; + + hostdata->pdma_residual = len; while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_DRQ | BASR_PHASE_MATCH, BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) { - CP_IO_TO_MEM(s, d, n); + int bytes; - transferred = d - dst - n; - hostdata->pdma_residual = len - transferred; + bytes = mac_pdma_recv(s, d, min(hostdata->pdma_residual, 512)); - /* No bus error. */ - if (n == 0) + if (bytes > 0) { + d += bytes; + hostdata->pdma_residual -= bytes; + } + + if (hostdata->pdma_residual == 0) return 0; - /* Target changed phase early? */ if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ, - BUS_AND_STATUS_REG, BASR_ACK, BASR_ACK, HZ / 64) < 0) - scmd_printk(KERN_ERR, hostdata->connected, + BUS_AND_STATUS_REG, BASR_ACK, + BASR_ACK, HZ / 64) < 0) + scmd_printk(KERN_DEBUG, hostdata->connected, "%s: !REQ and !ACK\n", __func__); if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH)) return 0; + if (bytes == 0) + udelay(MAC_PDMA_DELAY); + + if (bytes >= 0) + continue; + dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host, - "%s: bus error (%d/%d)\n", __func__, transferred, len); + "%s: bus error (%d/%d)\n", __func__, d - dst, len); NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host); - d = dst + transferred; - n = len - transferred; + return -1; } scmd_printk(KERN_ERR, hostdata->connected, @@ -192,93 +311,27 @@ static inline int macscsi_pread(struct NCR5380_hostdata *hostdata, return -1; } - -#define CP_MEM_TO_IO(s,d,n) \ -__asm__ __volatile__ \ - (" cmp.w #4,%2\n" \ - " bls 8f\n" \ - " move.w %0,%%d0\n" \ - " neg.b %%d0\n" \ - " and.w #3,%%d0\n" \ - " sub.w %%d0,%2\n" \ - " bra 2f\n" \ - " 1: move.b (%0)+,(%1)\n" \ - " 2: dbf %%d0,1b\n" \ - " move.w %2,%%d0\n" \ - " lsr.w #5,%%d0\n" \ - " bra 4f\n" \ - " 3: move.l (%0)+,(%1)\n" \ - "31: move.l (%0)+,(%1)\n" \ - "32: move.l (%0)+,(%1)\n" \ - "33: move.l (%0)+,(%1)\n" \ - "34: move.l (%0)+,(%1)\n" \ - "35: move.l (%0)+,(%1)\n" \ - "36: move.l (%0)+,(%1)\n" \ - "37: move.l (%0)+,(%1)\n" \ - " 4: dbf %%d0,3b\n" \ - " move.w %2,%%d0\n" \ - " lsr.w #2,%%d0\n" \ - " and.w #7,%%d0\n" \ - " bra 6f\n" \ - " 5: move.l (%0)+,(%1)\n" \ - " 6: dbf %%d0,5b\n" \ - " and.w #3,%2\n" \ - " bra 8f\n" \ - " 7: move.b (%0)+,(%1)\n" \ - " 8: dbf %2,7b\n" \ - " moveq.l #0, %2\n" \ - " 9: \n" \ - ".section .fixup,\"ax\"\n" \ - " .even\n" \ - "91: moveq.l #1, %2\n" \ - " jra 9b\n" \ - "94: moveq.l #4, %2\n" \ - " jra 9b\n" \ - ".previous\n" \ - ".section __ex_table,\"a\"\n" \ - " .align 4\n" \ - " .long 1b,91b\n" \ - " .long 3b,94b\n" \ - " .long 31b,94b\n" \ - " .long 32b,94b\n" \ - " .long 33b,94b\n" \ - " .long 34b,94b\n" \ - " .long 35b,94b\n" \ - " .long 36b,94b\n" \ - " .long 37b,94b\n" \ - " .long 5b,94b\n" \ - " .long 7b,91b\n" \ - ".previous" \ - : "=a"(s), "=a"(d), "=d"(n) \ - : "0"(s), "1"(d), "2"(n) \ - : "d0") - static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, unsigned char *src, int len) { unsigned char *s = src; u8 __iomem *d = hostdata->pdma_io + (OUTPUT_DATA_REG << 4); - int n = len; - int transferred; + + hostdata->pdma_residual = len; while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_DRQ | BASR_PHASE_MATCH, BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) { - CP_MEM_TO_IO(s, d, n); + int bytes; - transferred = s - src - n; - hostdata->pdma_residual = len - transferred; + bytes = mac_pdma_send(s, d, min(hostdata->pdma_residual, 512)); - /* Target changed phase early? */ - if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ, - BUS_AND_STATUS_REG, BASR_ACK, BASR_ACK, HZ / 64) < 0) - scmd_printk(KERN_ERR, hostdata->connected, - "%s: !REQ and !ACK\n", __func__); - if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH)) - return 0; + if (bytes > 0) { + s += bytes; + hostdata->pdma_residual -= bytes; + } - /* No bus error. */ - if (n == 0) { + if (hostdata->pdma_residual == 0) { if (NCR5380_poll_politely(hostdata, TARGET_COMMAND_REG, TCR_LAST_BYTE_SENT, TCR_LAST_BYTE_SENT, HZ / 64) < 0) @@ -287,17 +340,29 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, return 0; } + if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ, + BUS_AND_STATUS_REG, BASR_ACK, + BASR_ACK, HZ / 64) < 0) + scmd_printk(KERN_DEBUG, hostdata->connected, + "%s: !REQ and !ACK\n", __func__); + if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH)) + return 0; + + if (bytes == 0) + udelay(MAC_PDMA_DELAY); + + if (bytes >= 0) + continue; + dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host, - "%s: bus error (%d/%d)\n", __func__, transferred, len); + "%s: bus error (%d/%d)\n", __func__, s - src, len); NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host); - s = src + transferred; - n = len - transferred; + return -1; } scmd_printk(KERN_ERR, hostdata->connected, "%s: phase mismatch or !DRQ\n", __func__); NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host); - return -1; } -- cgit v1.2.3 From 8fb9a64eb6e6fe502187c154434729871d9e5578 Mon Sep 17 00:00:00 2001 From: Finn Thain Date: Sun, 9 Jun 2019 11:19:11 +1000 Subject: scsi: mac_scsi: Enable PDMA on Mac IIfx Add support for Apple's custom "SCSI DMA" chip. This patch doesn't make use of its DMA capability. Just the PDMA capability is sufficient to improve sequential read throughput by a factor of 5. Cc: Michael Schmitz Cc: Joshua Thompson Cc: Geert Uytterhoeven Signed-off-by: Finn Thain Tested-by: Stan Johnson Tested-by: Michael Schmitz Acked-by: Geert Uytterhoeven Signed-off-by: Martin K. Petersen --- drivers/scsi/mac_scsi.c | 47 +++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 39 insertions(+), 8 deletions(-) (limited to 'drivers/scsi/mac_scsi.c') diff --git a/drivers/scsi/mac_scsi.c b/drivers/scsi/mac_scsi.c index 27364b71e833..8fbec1768bbf 100644 --- a/drivers/scsi/mac_scsi.c +++ b/drivers/scsi/mac_scsi.c @@ -24,6 +24,7 @@ #include #include +#include #include #include @@ -262,11 +263,22 @@ out: return addr - start; } +/* The "SCSI DMA" chip on the IIfx implements this register. */ +#define CTRL_REG 0x8 +#define CTRL_INTERRUPTS_ENABLE BIT(1) +#define CTRL_HANDSHAKE_MODE BIT(3) + +static inline void write_ctrl_reg(struct NCR5380_hostdata *hostdata, u32 value) +{ + out_be32(hostdata->io + (CTRL_REG << 4), value); +} + static inline int macscsi_pread(struct NCR5380_hostdata *hostdata, unsigned char *dst, int len) { u8 __iomem *s = hostdata->pdma_io + (INPUT_DATA_REG << 4); unsigned char *d = dst; + int result = 0; hostdata->pdma_residual = len; @@ -275,6 +287,10 @@ static inline int macscsi_pread(struct NCR5380_hostdata *hostdata, BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) { int bytes; + if (macintosh_config->ident == MAC_MODEL_IIFX) + write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE | + CTRL_INTERRUPTS_ENABLE); + bytes = mac_pdma_recv(s, d, min(hostdata->pdma_residual, 512)); if (bytes > 0) { @@ -283,7 +299,7 @@ static inline int macscsi_pread(struct NCR5380_hostdata *hostdata, } if (hostdata->pdma_residual == 0) - return 0; + goto out; if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ, BUS_AND_STATUS_REG, BASR_ACK, @@ -291,7 +307,7 @@ static inline int macscsi_pread(struct NCR5380_hostdata *hostdata, scmd_printk(KERN_DEBUG, hostdata->connected, "%s: !REQ and !ACK\n", __func__); if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH)) - return 0; + goto out; if (bytes == 0) udelay(MAC_PDMA_DELAY); @@ -302,13 +318,18 @@ static inline int macscsi_pread(struct NCR5380_hostdata *hostdata, dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host, "%s: bus error (%d/%d)\n", __func__, d - dst, len); NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host); - return -1; + result = -1; + goto out; } scmd_printk(KERN_ERR, hostdata->connected, "%s: phase mismatch or !DRQ\n", __func__); NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host); - return -1; + result = -1; +out: + if (macintosh_config->ident == MAC_MODEL_IIFX) + write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE); + return result; } static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, @@ -316,6 +337,7 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, { unsigned char *s = src; u8 __iomem *d = hostdata->pdma_io + (OUTPUT_DATA_REG << 4); + int result = 0; hostdata->pdma_residual = len; @@ -324,6 +346,10 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) { int bytes; + if (macintosh_config->ident == MAC_MODEL_IIFX) + write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE | + CTRL_INTERRUPTS_ENABLE); + bytes = mac_pdma_send(s, d, min(hostdata->pdma_residual, 512)); if (bytes > 0) { @@ -337,7 +363,7 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, TCR_LAST_BYTE_SENT, HZ / 64) < 0) scmd_printk(KERN_ERR, hostdata->connected, "%s: Last Byte Sent timeout\n", __func__); - return 0; + goto out; } if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ, @@ -346,7 +372,7 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, scmd_printk(KERN_DEBUG, hostdata->connected, "%s: !REQ and !ACK\n", __func__); if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH)) - return 0; + goto out; if (bytes == 0) udelay(MAC_PDMA_DELAY); @@ -357,13 +383,18 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host, "%s: bus error (%d/%d)\n", __func__, s - src, len); NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host); - return -1; + result = -1; + goto out; } scmd_printk(KERN_ERR, hostdata->connected, "%s: phase mismatch or !DRQ\n", __func__); NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host); - return -1; + result = -1; +out: + if (macintosh_config->ident == MAC_MODEL_IIFX) + write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE); + return result; } static int macscsi_dma_xfer_len(struct NCR5380_hostdata *hostdata, -- cgit v1.2.3 From 7c1f3e3447a13a91e95fff6bac7312858c90b0cf Mon Sep 17 00:00:00 2001 From: Finn Thain Date: Sun, 9 Jun 2019 11:19:11 +1000 Subject: scsi: mac_scsi: Treat Last Byte Sent time-out as failure A system bus error during a PDMA send operation can result in bytes being lost. Theoretically that could cause the target to remain in DATA OUT phase and the initiator (expecting a phase change) would time-out waiting for the Last Byte Sent flag. Should that happen, fail the transfer so the core driver will stop using PDMA with this target. Cc: Michael Schmitz Signed-off-by: Finn Thain Tested-by: Stan Johnson Tested-by: Michael Schmitz Signed-off-by: Martin K. Petersen --- drivers/scsi/mac_scsi.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/scsi/mac_scsi.c') diff --git a/drivers/scsi/mac_scsi.c b/drivers/scsi/mac_scsi.c index 8fbec1768bbf..658a719cfcba 100644 --- a/drivers/scsi/mac_scsi.c +++ b/drivers/scsi/mac_scsi.c @@ -360,9 +360,12 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, if (hostdata->pdma_residual == 0) { if (NCR5380_poll_politely(hostdata, TARGET_COMMAND_REG, TCR_LAST_BYTE_SENT, - TCR_LAST_BYTE_SENT, HZ / 64) < 0) + TCR_LAST_BYTE_SENT, + HZ / 64) < 0) { scmd_printk(KERN_ERR, hostdata->connected, "%s: Last Byte Sent timeout\n", __func__); + result = -1; + } goto out; } -- cgit v1.2.3