Setting To Ignore Parity For Initiator Mode Data Transfers

lib/BlueSCSI_platform_RP2040/scsiHostPhy.cpp

@@ -1,4 +1,5 @@
 // Copyright (c) 2022 Rabbit Hole Computing™
+// Copyright (c) 2024 Tech by Androda, LLC
 
 #include "scsiHostPhy.h"
 #include "BlueSCSI_platform.h"
@@ -13,6 +14,7 @@ extern "C" {
 }
 
 volatile int g_scsiHostPhyReset;
+bool perform_parity_checking = true;
 
 // Release bus and pulse RST signal, initialize PHY to host mode.
 void scsiHostPhyReset(void)
@@ -168,7 +170,7 @@ static inline void scsiHostWriteOneByte(uint8_t value)
 }
 
 // Read one byte from SCSI target using the handshake mechanism.
-static inline uint8_t scsiHostReadOneByte(int* parityError)
+static inline uint8_t scsiHostReadOneByte(int* parityError, uint32_t *parityResult)
 {
     SCSIHOST_WAIT_ACTIVE(REQ);
     uint16_t r = SCSI_IN_DATA();
@@ -178,8 +180,8 @@ static inline uint8_t scsiHostReadOneByte(int* parityError)
 
     if (parityError && r != (g_scsi_parity_lookup[r & 0xFF] ^ SCSI_IO_DATA_MASK))
     {
-        log("Parity error in scsiReadOneByte(): ", (uint32_t)r);
         *parityError = 1;
+        *parityResult = (uint32_t)r;
     }
 
     return (uint8_t)r;
@@ -213,6 +215,7 @@ uint32_t scsiHostWrite(const uint8_t *data, uint32_t count)
 uint32_t scsiHostRead(uint8_t *data, uint32_t count)
 {
     int parityError = 0;
+    uint32_t parityResult;
     uint32_t fullcount = count;
 
     int cd_start = SCSI_IN(CD);
@@ -221,7 +224,12 @@ uint32_t scsiHostRead(uint8_t *data, uint32_t count)
     if ((count & 1) == 0 && ((uint32_t)data & 1) == 0)
     {
         // Even number of bytes, use accelerated routine
-        count = scsi_accel_host_read(data, count, &parityError, &g_scsiHostPhyReset);
+        count = scsi_accel_host_read(data, count, &parityError, &parityResult, &g_scsiHostPhyReset);
+        if (parityError && perform_parity_checking) {
+            log("Parity error in scsi_accel_host_read(): ", parityResult);
+        } else {
+            parityError = 0;
+        }
     }
     else
     {
@@ -235,8 +243,12 @@ uint32_t scsiHostRead(uint8_t *data, uint32_t count)
                     count = i;
                 }
             }
-
-            data[i] = scsiHostReadOneByte(&parityError);
+            data[i] = scsiHostReadOneByte(&parityError, &parityResult);
+            if (parityError && perform_parity_checking) {
+                log("Parity error in scsiReadOneByte(): ", parityResult);
+            } else {
+                parityError = 0;
+            }
         }
     }
 
@@ -264,3 +276,7 @@ void scsiHostPhyRelease()
     SCSI_RELEASE_OUTPUTS();
     SCSI_RELEASE_DATA_REQ();
 }
+
+void setInitiatorModeParityCheck(bool checkParity) {
+    perform_parity_checking = checkParity;
+}

lib/BlueSCSI_platform_RP2040/scsiHostPhy.h

@@ -30,3 +30,5 @@ uint32_t scsiHostRead(uint8_t *data, uint32_t count);
 
 // Release all bus signals
 void scsiHostPhyRelease();
+
+void setInitiatorModeParityCheck(bool checkParity);

lib/BlueSCSI_platform_RP2040/scsi_accel_host.cpp

@@ -1,5 +1,6 @@
 // Accelerated SCSI subroutines for SCSI initiator/host side communication
 // Copyright (c) 2022 Rabbit Hole Computing™
+// Copyright (c) 2024 Tech by Androda, LLC
 
 #include "scsi_accel_host.h"
 #include "BlueSCSI_platform.h"
@@ -65,7 +66,7 @@ static void scsi_accel_host_config_gpio()
     }
 }
 
-uint32_t scsi_accel_host_read(uint8_t *buf, uint32_t count, int *parityError, volatile int *resetFlag)
+uint32_t scsi_accel_host_read(uint8_t *buf, uint32_t count, int *parityError, uint32_t *parityResult, volatile int *resetFlag)
 {
     // Currently this method just reads from the PIO RX fifo directly in software loop.
     // The SD card access is parallelized using DMA, so there is limited benefit from using DMA here.
@@ -117,8 +118,8 @@ uint32_t scsi_accel_host_read(uint8_t *buf, uint32_t count, int *parityError, vo
     uint8_t byte1 = ~(paritycheck >> 16);
     if (paritycheck != ((g_scsi_parity_lookup[byte1] << 16) | g_scsi_parity_lookup[byte0]))
     {
-        log("Parity error in scsi_accel_host_read(): ", paritycheck);
         *parityError = 1;
+        *parityResult = paritycheck;
     }
 
     g_scsi_host_state = SCSIHOST_IDLE;

lib/BlueSCSI_platform_RP2040/scsi_accel_host.h

@@ -8,4 +8,4 @@ void scsi_accel_host_init();
 
 // Read data from SCSI bus.
 // Number of bytes to read must be divisible by two.
-uint32_t scsi_accel_host_read(uint8_t *buf, uint32_t count, int *parityError, volatile int *resetFlag);
+uint32_t scsi_accel_host_read(uint8_t *buf, uint32_t count, int *parityError, uint32_t *parityResult, volatile int *resetFlag);

src/BlueSCSI.cpp

@@ -610,6 +610,11 @@ extern "C" void bluescsi_setup(void)
     if (ini_getbool("SCSI", "InitiatorMode", false, CONFIGFILE))
     {
       platform_enable_initiator_mode();
+      if (! ini_getbool("SCSI", "InitiatorParity", true, CONFIGFILE))
+      {
+        log("Initiator Mode Skipping Parity Check.");
+        setInitiatorModeParityCheck(false);
+      }
     }
     if (SD.clusterCount() == 0)
     {