Deactivated ISP interface in exception handler

src/Targets/Microchip/AVR/AVR8/Avr8.cpp

@@ -791,6 +791,7 @@ namespace Bloom::Targets::Microchip::Avr::Avr8Bit
                 "see the Bloom license at " + Paths::homeDomainName() + "/license"
         );
 
+        try {
             Logger::info("Reading target signature via ISP");
             const auto ispDeviceId = this->avrIspInterface->getDeviceId();
 
@@ -809,15 +810,15 @@ namespace Bloom::Targets::Microchip::Avr::Avr8Bit
                 : this->avrIspInterface->readFuse(spienFuseBitsDescriptor->fuseType).value;
 
             /*
-         * Keep in mind that, for AVR fuses and lock bits, a set bit (1) means the fuse/lock is cleared, and a cleared
+             * Keep in mind that, for AVR fuses and lock bits, a set bit (0b1) means the fuse/lock is cleared, and a
-         * bit (0), means the fuse/lock is set.
+             * cleared bit (0b0), means the fuse/lock is set.
              */
 
             if ((spienFuseByte & spienFuseBitsDescriptor->bitMask) != 0) {
                 /*
-             * If we get here, something is very wrong. The SPIEN (SPI enable) fuse bit appears to be cleared, but this
+                 * If we get here, something is very wrong. The SPIEN (SPI enable) fuse bit appears to be cleared, but
-             * is not possible because we're connected to the target via the SPI (the ISP interface uses a physical SPI
+                 * this is not possible because we're connected to the target via the SPI (the ISP interface uses a
-             * between the debug tool and the target).
+                 * physical SPI between the debug tool and the target).
                  *
                  * This could be (and likely is) caused by incorrect data for the SPIEN fuse bit, in the TDF (which was
                  * used to construct the spienFuseBitsDescriptor). And if the data for the SPIEN fuse bit is incorrect,
@@ -835,24 +836,27 @@ namespace Bloom::Targets::Microchip::Avr::Avr8Bit
 
             if (static_cast<bool>(dwenFuseByte & dwenFuseBitsDescriptor->bitMask) == !setFuse) {
                 /*
-             * The DWEN fuse appears to already be set to the desired value. This may be a result of incorrect data in
+                 * The DWEN fuse appears to already be set to the desired value. This may be a result of incorrect data
-             * the TDF, but we're not taking any chances.
+                 * in the TDF, but we're not taking any chances.
                  *
-             * We don't throw an exception here, because we don't know if this is due to an error, or if the fuse bit
+                 * We don't throw an exception here, because we don't know if this is due to an error, or if the fuse
-             * is simply already set to the desired value.
+                 * bit is simply already set to the desired value.
                  */
+                Logger::debug("DWEN fuse bit already set to desired value - aborting update operation");
+
+                this->avrIspInterface->deactivate();
                 return;
             }
 
             const auto lockBitByte = this->avrIspInterface->readLockBitByte();
             if (lockBitByte != 0xFF) {
                 /*
-             * There is at least one lock bit that is set. Setting the DWEN fuse bit with the lock bits set will
+                 * There is at least one lock bit that is set. Setting the DWEN fuse bit with the lock bits set may
                  * brick the device. We must abort.
                  */
                 throw Exception(
-                "At least one lock bit has been set - updating the DWEN fuse bit could potentially brick the "
+                    "At least one lock bit has been set - updating the DWEN fuse bit could potentially brick "
-                    "target."
+                        "the target."
                 );
             }
 
@@ -868,11 +872,16 @@ namespace Bloom::Targets::Microchip::Avr::Avr8Bit
             this->avrIspInterface->programFuse(newFuse);
 
             if (this->avrIspInterface->readFuse(dwenFuseBitsDescriptor->fuseType).value != newFuse.value) {
-            Logger::error("Failed to program fuse bit - post-program value check failed");
+                throw Exception("Failed to program fuse bit - post-program value check failed");
             }
 
             Logger::info("DWEN fuse bit successfully updated");
 
             this->avrIspInterface->deactivate();
+
+        } catch (const Exception& exception) {
+            this->avrIspInterface->deactivate();
+            throw exception;
+        }
     }
 }