Commit bc46bae6 authored by Hans de Goede's avatar Hans de Goede Committed by Mauro Carvalho Chehab
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[media] gspca_xirlink_cit: various usb bandwidth allocation improvements / fixes 



The following usb bandwidth allocation changes were made to the ibm netcam
pro code:
- Don't restart negotiation at max packet size on stop0, as that gets called
  by gspca_main during negotiation. Move this to sd_isoc_init.
- Don't ask for full bandwidth when running at 160x120, that does not need
  full bandwidth
- Make minimum acceptable bandwidth depend upon resolution

[mchehab@redhat.com: Fix CodingStyle problems at switch statements]
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 2661da47

drivers/media/video/gspca/xirlink_cit.c

+43 −10
Original line number Diff line number Diff line
@@ -2769,16 +2769,55 @@ static int sd_start(struct gspca_dev *gspca_dev) 
	return 0;

}



static int sd_isoc_init(struct gspca_dev *gspca_dev)

{

	struct usb_host_interface *alt;

	int max_packet_size;



	switch (gspca_dev->width) {

	case 160:

		max_packet_size = 450;

		break;

	case 176:

		max_packet_size = 600;

		break;

	default:

		max_packet_size = 1022;

		break;

	}



	/* Start isoc bandwidth "negotiation" at max isoc bandwidth */

	alt = &gspca_dev->dev->config->intf_cache[0]->altsetting[1];

	alt->endpoint[0].desc.wMaxPacketSize = cpu_to_le16(max_packet_size);



	return 0;

}



static int sd_isoc_nego(struct gspca_dev *gspca_dev)

{

	int ret, packet_size;

	int ret, packet_size, min_packet_size;

	struct usb_host_interface *alt;



	switch (gspca_dev->width) {

	case 160:

		min_packet_size = 200;

		break;

	case 176:

		min_packet_size = 266;

		break;

	default:

		min_packet_size = 400;

		break;

	}



	alt = &gspca_dev->dev->config->intf_cache[0]->altsetting[1];

	packet_size = le16_to_cpu(alt->endpoint[0].desc.wMaxPacketSize);

	packet_size -= 100;

	if (packet_size < 300)

	if (packet_size <= min_packet_size)

		return -EIO;



	packet_size -= 100;

	if (packet_size < min_packet_size)

		packet_size = min_packet_size;

	alt->endpoint[0].desc.wMaxPacketSize = cpu_to_le16(packet_size);



	ret = usb_set_interface(gspca_dev->dev, gspca_dev->iface, 1);
@@ -2796,15 +2835,12 @@ static void sd_stopN(struct gspca_dev *gspca_dev) 
static void sd_stop0(struct gspca_dev *gspca_dev)

{

	struct sd *sd = (struct sd *) gspca_dev;

	struct usb_host_interface *alt;



	/* We cannot use gspca_dev->present here as that is not set when

	   sd_init gets called and we get called from sd_init */

	if (!gspca_dev->dev)

		return;



	alt = &gspca_dev->dev->config->intf_cache[0]->altsetting[1];



	switch (sd->model) {

	case CIT_MODEL0:

		/* HDG windows does this, but it causes the cams autogain to
@@ -2859,10 +2895,6 @@ static void sd_stop0(struct gspca_dev *gspca_dev) 
		   restarting the stream after this */

		/* cit_write_reg(gspca_dev, 0x0000, 0x0112); */

		cit_write_reg(gspca_dev, 0x00c0, 0x0100);



		/* Start isoc bandwidth "negotiation" at max isoc bandwith

		   next stream start */

		alt->endpoint[0].desc.wMaxPacketSize = cpu_to_le16(1022);

		break;

	}

}
@@ -3179,6 +3211,7 @@ static const struct sd_desc sd_desc_isoc_nego = { 
	.config = sd_config,

	.init = sd_init,

	.start = sd_start,

	.isoc_init = sd_isoc_init,

	.isoc_nego = sd_isoc_nego,

	.stopN = sd_stopN,

	.stop0 = sd_stop0,