[LINUX PATCH] usb: gadget: Configure bulk maxburst through module parameter in gadget zero.

[Manish Narani <manish.narani@xilinx.com>]

This patch adds support to configure bulk maxburst through
module parameter. This parameter can be used to modify bulk
maxburst in case if one wants to measure peak Bulk/Isoc-IN/OUT
performance.

Signed-off-by: Manish Narani <mnarani@xilinx.com>
---
 drivers/usb/gadget/function/f_sourcesink.c |   14 ++++++++++++++
 drivers/usb/gadget/function/g_zero.h       |    2 ++
 drivers/usb/gadget/legacy/zero.c           |    5 +++++
 3 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/drivers/usb/gadget/function/f_sourcesink.c b/drivers/usb/gadget/function/f_sourcesink.c
index df0189d..81274ba 100644
--- a/drivers/usb/gadget/function/f_sourcesink.c
+++ b/drivers/usb/gadget/function/f_sourcesink.c
@@ -49,6 +49,7 @@ struct f_sourcesink {
 	unsigned isoc_maxpacket;
 	unsigned isoc_mult;
 	unsigned isoc_maxburst;
+	unsigned bulk_maxburst;
 	unsigned buflen;
 	unsigned bulk_qlen;
 	unsigned iso_qlen;
@@ -334,6 +335,10 @@ sourcesink_bind(struct usb_configuration *c, struct usb_function *f)
 	source_sink_intf_alt0.bInterfaceNumber = id;
 	source_sink_intf_alt1.bInterfaceNumber = id;
 
+	/* sanity check the bulk module parameters */
+	if (ss->bulk_maxburst > 15)
+		ss->bulk_maxburst = 15;
+
 	/* allocate bulk endpoints */
 	ss->in_ep = usb_ep_autoconfig(cdev->gadget, &fs_source_desc);
 	if (!ss->in_ep) {
@@ -347,6 +352,14 @@ autoconf_fail:
 	if (!ss->out_ep)
 		goto autoconf_fail;
 
+	/*
+	 * Fill in the SS bulk descriptors from the module parameters.
+	 * We assume that the user knows what they are doing and won't
+	 * give parameters that their UDC doesn't support.
+	 */
+	ss_source_comp_desc.bMaxBurst = ss->bulk_maxburst;
+	ss_sink_comp_desc.bMaxBurst = ss->bulk_maxburst;
+
 	/* sanity check the isoc module parameters */
 	if (ss->isoc_interval < 1)
 		ss->isoc_interval = 1;
@@ -857,6 +870,7 @@ static struct usb_function *source_sink_alloc_func(
 	ss->isoc_maxpacket = ss_opts->isoc_maxpacket;
 	ss->isoc_mult = ss_opts->isoc_mult;
 	ss->isoc_maxburst = ss_opts->isoc_maxburst;
+	ss->bulk_maxburst = ss_opts->bulk_maxburst;
 	ss->buflen = ss_opts->bulk_buflen;
 	ss->bulk_qlen = ss_opts->bulk_qlen;
 	ss->iso_qlen = ss_opts->iso_qlen;
diff --git a/drivers/usb/gadget/function/g_zero.h b/drivers/usb/gadget/function/g_zero.h
index 492924d..b3234e7 100644
--- a/drivers/usb/gadget/function/g_zero.h
+++ b/drivers/usb/gadget/function/g_zero.h
@@ -19,6 +19,7 @@ struct usb_zero_options {
 	unsigned isoc_maxpacket;
 	unsigned isoc_mult;
 	unsigned isoc_maxburst;
+	unsigned bulk_maxburst;
 	unsigned bulk_buflen;
 	unsigned qlen;
 	unsigned ss_bulk_qlen;
@@ -32,6 +33,7 @@ struct f_ss_opts {
 	unsigned isoc_maxpacket;
 	unsigned isoc_mult;
 	unsigned isoc_maxburst;
+	unsigned bulk_maxburst;
 	unsigned bulk_buflen;
 	unsigned bulk_qlen;
 	unsigned iso_qlen;
diff --git a/drivers/usb/gadget/legacy/zero.c b/drivers/usb/gadget/legacy/zero.c
index d02e2ce..c88f5e0 100644
--- a/drivers/usb/gadget/legacy/zero.c
+++ b/drivers/usb/gadget/legacy/zero.c
@@ -247,6 +247,10 @@ MODULE_PARM_DESC(isoc_maxpacket, "0 - 1023 (fs), 0 - 1024 (hs/ss)");
 module_param_named(isoc_mult, gzero_options.isoc_mult, uint, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(isoc_mult, "0 - 2 (hs/ss only)");
 
+module_param_named(bulk_maxburst, gzero_options.bulk_maxburst, uint,
+		S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(bulk_maxburst, "0 - 15 (ss only)");
+
 module_param_named(isoc_maxburst, gzero_options.isoc_maxburst, uint,
 		S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(isoc_maxburst, "0 - 15 (ss only)");
@@ -294,6 +298,7 @@ static int zero_bind(struct usb_composite_dev *cdev)
 	ss_opts->isoc_maxpacket = gzero_options.isoc_maxpacket;
 	ss_opts->isoc_mult = gzero_options.isoc_mult;
 	ss_opts->isoc_maxburst = gzero_options.isoc_maxburst;
+	ss_opts->bulk_maxburst = gzero_options.bulk_maxburst;
 	ss_opts->bulk_buflen = gzero_options.bulk_buflen;
 	ss_opts->bulk_qlen = gzero_options.ss_bulk_qlen;
 	ss_opts->iso_qlen = gzero_options.ss_iso_qlen;
-- 
1.7.1