From bc46bae6373c87897959c7aa8fb9f6c4218695b8 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Tue, 26 Oct 2010 11:18:59 -0300 Subject: [PATCH] [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: Hans de Goede Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/gspca/xirlink_cit.c | 53 ++++++++++++++++++++++++++------- 1 file changed, 43 insertions(+), 10 deletions(-) diff --git a/drivers/media/video/gspca/xirlink_cit.c b/drivers/media/video/gspca/xirlink_cit.c index 8715577..daeda2c 100644 --- a/drivers/media/video/gspca/xirlink_cit.c +++ b/drivers/media/video/gspca/xirlink_cit.c @@ -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, -- 2.7.4