Fixed MTP to work with TWRP

arch/um/kernel/sigio.c

@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
+ * Licensed under the GPL
+ */
+
+#include <linux/interrupt.h>
+#include <irq_kern.h>
+#include <os.h>
+#include <sigio.h>
+
+/* Protected by sigio_lock() called from write_sigio_workaround */
+static int sigio_irq_fd = -1;
+
+static irqreturn_t sigio_interrupt(int irq, void *data)
+{
+	char c;
+
+	os_read_file(sigio_irq_fd, &c, sizeof(c));
+	reactivate_fd(sigio_irq_fd, SIGIO_WRITE_IRQ);
+	return IRQ_HANDLED;
+}
+
+int write_sigio_irq(int fd)
+{
+	int err;
+
+	err = um_request_irq(SIGIO_WRITE_IRQ, fd, IRQ_READ, sigio_interrupt,
+			     0, "write sigio", NULL);
+	if (err) {
+		printk(KERN_ERR "write_sigio_irq : um_request_irq failed, "
+		       "err = %d\n", err);
+		return -1;
+	}
+	sigio_irq_fd = fd;
+	return 0;
+}
+
+/* These are called from os-Linux/sigio.c to protect its pollfds arrays. */
+static DEFINE_SPINLOCK(sigio_spinlock);
+
+void sigio_lock(void)
+{
+	spin_lock(&sigio_spinlock);
+}
+
+void sigio_unlock(void)
+{
+	spin_unlock(&sigio_spinlock);
+}