usb: m66592-udc buffer management update

This patch updates the m66592-udc buffer management code.

Use fixed buffers for bulk and isochronous pipes, also make
sure to handle the isochronous-as-bulk case. With fixed buffers
there is no need to keep track of used buffers with bi_bufnum.

Also, this fixes a potential buffer offset problem where the
base offset incorrectly varies with the number of pipes used.

With this patch applied it is possible to use m66592-udc for
both Ethernet and Serial using CONFIG_USB_CDC_COMPOSITE.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/usb/gadget/m66592-udc.c

@@ -37,7 +37,7 @@ MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Yoshihiro Shimoda");
 MODULE_ALIAS("platform:m66592_udc");
 
-#define DRIVER_VERSION	"18 Oct 2007"
+#define DRIVER_VERSION	"26 Jun 2009"
 
 /* module parameters */
 #if defined(CONFIG_SUPERH_BUILT_IN_M66592)
@@ -276,24 +276,27 @@ static int pipe_buffer_setting(struct m66592 *m66592,
 		buf_bsize = 0;
 		break;
 	case M66592_BULK:
-		bufnum = m66592->bi_bufnum +
-			 (info->pipe - M66592_BASE_PIPENUM_BULK) * 16;
-		m66592->bi_bufnum += 16;
+		/* isochronous pipes may be used as bulk pipes */
+		if (info->pipe > M66592_BASE_PIPENUM_BULK)
+			bufnum = info->pipe - M66592_BASE_PIPENUM_BULK;
+		else
+			bufnum = info->pipe - M66592_BASE_PIPENUM_ISOC;
+
+		bufnum = M66592_BASE_BUFNUM + (bufnum * 16);
 		buf_bsize = 7;
 		pipecfg |= M66592_DBLB;
 		if (!info->dir_in)
 			pipecfg |= M66592_SHTNAK;
 		break;
 	case M66592_ISO:
-		bufnum = m66592->bi_bufnum +
+		bufnum = M66592_BASE_BUFNUM +
 			 (info->pipe - M66592_BASE_PIPENUM_ISOC) * 16;
-		m66592->bi_bufnum += 16;
 		buf_bsize = 7;
 		break;
 	}
-	if (m66592->bi_bufnum > M66592_MAX_BUFNUM) {
-		pr_err("m66592 pipe memory is insufficient(%d)\n",
-				m66592->bi_bufnum);
+
+	if (buf_bsize && ((bufnum + 16) >= M66592_MAX_BUFNUM)) {
+		pr_err("m66592 pipe memory is insufficient\n");
 		return -ENOMEM;
 	}
 
@@ -313,17 +316,6 @@ static void pipe_buffer_release(struct m66592 *m66592,
 	if (info->pipe == 0)
 		return;
 
-	switch (info->type) {
-	case M66592_BULK:
-		if (is_bulk_pipe(info->pipe))
-			m66592->bi_bufnum -= 16;
-		break;
-	case M66592_ISO:
-		if (is_isoc_pipe(info->pipe))
-			m66592->bi_bufnum -= 16;
-		break;
-	}
-
 	if (is_bulk_pipe(info->pipe)) {
 		m66592->bulk--;
 	} else if (is_interrupt_pipe(info->pipe))
@@ -1603,8 +1595,6 @@ static int __init m66592_probe(struct platform_device *pdev)
 	m66592->timer.data = (unsigned long)m66592;
 	m66592->reg = reg;
 
-	m66592->bi_bufnum = M66592_BASE_BUFNUM;
-
 	ret = request_irq(irq, m66592_irq, IRQF_DISABLED | IRQF_SHARED,
 			udc_name, m66592);
 	if (ret < 0) {

drivers/usb/gadget/m66592-udc.h

@@ -506,7 +506,6 @@ struct m66592 {
 	int interrupt;
 	int isochronous;
 	int num_dma;
-	int bi_bufnum;	/* bulk and isochronous's bufnum */
 };
 
 #define gadget_to_m66592(_gadget) container_of(_gadget, struct m66592, gadget)