Use LCDBuffer read-only when doing interrupt transfers.

Author: netfab

src/bin/daemon/LCDScreenPluginsManager.cpp

@@ -166,7 +166,7 @@ const bool LCDScreenPluginsManager::findOneLCDScreenPlugin(const uint64_t LCDPlu
 	return ret;
 }
 
-PixelsData & LCDScreenPluginsManager::getNextLCDScreenBuffer(
+const PixelsData & LCDScreenPluginsManager::getNextLCDScreenBuffer(
 	const std::string & LCDKey,
 	const uint64_t LCDPluginsMask1
 ) {

src/bin/daemon/LCDScreenPluginsManager.hpp

@@ -48,7 +48,7 @@ class LCDScreenPluginsManager
 
 		const bool findOneLCDScreenPlugin(const uint64_t LCDPluginsMask1) const;
 
-		PixelsData & getNextLCDScreenBuffer(
+		const PixelsData & getNextLCDScreenBuffer(
 			const std::string & LCDKey,
 			const uint64_t LCDPluginsMask1
 		);

src/bin/daemon/hidapi.cpp

@@ -2,7 +2,7 @@
  *
  *	This file is part of GLogiK project.
  *	GLogiK, daemon to handle special features on gaming keyboards
- *	Copyright (C) 2016-2020  Fabrice Delliaux <[email protected]>
+ *	Copyright (C) 2016-2021  Fabrice Delliaux <[email protected]>
  *
  *	This program is free software: you can redistribute it and/or modify
  *	it under the terms of the GNU General Public License as published by
@@ -183,7 +183,7 @@ int hidapi::performKeysInterruptTransfer(
 
 int hidapi::performLCDScreenInterruptTransfer(
 	USBDevice & device,
-	unsigned char* buffer,
+	const unsigned char * buffer,
 	int bufferLength,
 	unsigned int timeout)
 {

src/bin/daemon/hidapi.hpp

@@ -2,7 +2,7 @@
  *
  *	This file is part of GLogiK project.
  *	GLogiK, daemon to handle special features on gaming keyboards
- *	Copyright (C) 2016-2020  Fabrice Delliaux <[email protected]>
+ *	Copyright (C) 2016-2021  Fabrice Delliaux <[email protected]>
  *
  *	This program is free software: you can redistribute it and/or modify
  *	it under the terms of the GNU General Public License as published by
@@ -55,7 +55,7 @@ class hidapi
 
 		int performLCDScreenInterruptTransfer(
 			USBDevice & device,
-			unsigned char* buffer,
+			const unsigned char * buffer,
 			int bufferLength,
 			unsigned int timeout
 		);

src/bin/daemon/keyboardDriver.cpp

@@ -555,12 +555,13 @@ void KeyboardDriver::LCDScreenLoop(const std::string & devID) {
 				LCDPluginsMask1 = device._LCDPluginsMask1;
 			}
 
-			PixelsData & LCDBuffer = device.getLCDPluginsManager()->getNextLCDScreenBuffer(LCDKey, LCDPluginsMask1);
+			const PixelsData & LCDBuffer = device.getLCDPluginsManager()->getNextLCDScreenBuffer(LCDKey, LCDPluginsMask1);
 			int ret = this->performLCDScreenInterruptTransfer(
 				device,
 				LCDBuffer.data(),
 				LCDBuffer.size(),
-				1000);
+				1000
+			);
 
 			auto interval = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::high_resolution_clock::now() - t1);
 			auto one = std::chrono::milliseconds( device.getLCDPluginsManager()->getPluginTiming() );
@@ -588,8 +589,13 @@ void KeyboardDriver::LCDScreenLoop(const std::string & devID) {
 		const uint64_t endscreen = toEnumType(LCDScreenPlugin::GK_LCD_ENDSCREEN);
 		/* make sure endscreen plugin is loaded before using it */
 		if( device.getLCDPluginsManager()->findOneLCDScreenPlugin( endscreen ) ) {
-			PixelsData & LCDBuffer = device.getLCDPluginsManager()->getNextLCDScreenBuffer("", endscreen);
-			int ret = this->performLCDScreenInterruptTransfer(device, LCDBuffer.data(), LCDBuffer.size(), 1000);
+			const PixelsData & LCDBuffer = device.getLCDPluginsManager()->getNextLCDScreenBuffer("", endscreen);
+			int ret = this->performLCDScreenInterruptTransfer(
+				device,
+				LCDBuffer.data(),
+				LCDBuffer.size(),
+				1000
+			);
 			if(ret != 0) {
 				GKSysLog(LOG_ERR, ERROR, "endscreen LCD refresh failure");
 			}

src/bin/daemon/keyboardDriver.hpp

@@ -165,7 +165,7 @@ class KeyboardDriver
 		) = 0;
 		virtual int performLCDScreenInterruptTransfer(
 			USBDevice & device,
-			unsigned char* buffer,
+			const unsigned char * buffer,
 			int bufferLength,
 			unsigned int timeout
 		) = 0;
@@ -241,7 +241,7 @@ class USBKeyboardDriver
 
 		int performLCDScreenInterruptTransfer(
 			USBDevice & device,
-			unsigned char* buffer,
+			const unsigned char * buffer,
 			int bufferLength,
 			unsigned int timeout
 		) override {

src/bin/daemon/libUSB.cpp

@@ -2,7 +2,7 @@
  *
  *	This file is part of GLogiK project.
  *	GLogiK, daemon to handle special features on gaming keyboards
- *	Copyright (C) 2016-2020  Fabrice Delliaux <[email protected]>
+ *	Copyright (C) 2016-2021  Fabrice Delliaux <[email protected]>
  *
  *	This program is free software: you can redistribute it and/or modify
  *	it under the terms of the GNU General Public License as published by
@@ -227,7 +227,7 @@ int LibUSB::performKeysInterruptTransfer(
 
 int LibUSB::performLCDScreenInterruptTransfer(
 	USBDevice & device,
-	unsigned char* buffer,
+	const unsigned char * buffer,
 	int bufferLength,
 	unsigned int timeout)
 {
@@ -239,10 +239,13 @@ int LibUSB::performLCDScreenInterruptTransfer(
 	int ret = 0;
 	{
 		std::lock_guard<std::mutex> lock(device._libUSBMutex);
+		/* here we assume that buffer will be used read-only by
+		 * interrupt_transfer since _LCDEndpoint direction is OUT
+		 * (host-to-device) */
 		ret = libusb_interrupt_transfer(
 			device._pUSBDeviceHandle,
 			device._LCDEndpoint,
-			buffer,
+			const_cast<unsigned char *>(buffer),
 			bufferLength,
 			&(device._lastLCDInterruptTransferLength),
 			timeout

src/bin/daemon/libUSB.hpp

@@ -2,7 +2,7 @@
  *
  *	This file is part of GLogiK project.
  *	GLogiK, daemon to handle special features on gaming keyboards
- *	Copyright (C) 2016-2020  Fabrice Delliaux <[email protected]>
+ *	Copyright (C) 2016-2021  Fabrice Delliaux <[email protected]>
  *
  *	This program is free software: you can redistribute it and/or modify
  *	it under the terms of the GNU General Public License as published by
@@ -55,7 +55,7 @@ class LibUSB
 
 		int performLCDScreenInterruptTransfer(
 			USBDevice & device,
-			unsigned char* buffer,
+			const unsigned char * buffer,
 			int bufferLength,
 			unsigned int timeout
 		);