From d685a483b8c92e3d0580b6c28e2ed531391c8c46 Mon Sep 17 00:00:00 2001 From: "Brett T. Warden" Date: Thu, 10 Jan 2008 04:33:31 -0300 Subject: [PATCH] V4L/DVB (7013): bw-qcam: add module parameter 'force_init' to skip polite auto-detection prior to direct initialization Setting force_init=1 bypasses the friendly auto-detection by polling the status register, and instead attempts to initialize the qcam directly. Not friendly to other parallel devices, but much more reliable than the auto-detection. Signed-off-by: Brett T. Warden Signed-off-by: Andrew Morton Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/bw-qcam.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/media/video/bw-qcam.c b/drivers/media/video/bw-qcam.c index 5842352559..032265383d 100644 --- a/drivers/media/video/bw-qcam.c +++ b/drivers/media/video/bw-qcam.c @@ -82,11 +82,16 @@ OTHER DEALINGS IN THE SOFTWARE. static unsigned int maxpoll=250; /* Maximum busy-loop count for qcam I/O */ static unsigned int yieldlines=4; /* Yield after this many during capture */ static int video_nr = -1; +static unsigned int force_init; /* Whether to probe aggressively */ module_param(maxpoll, int, 0); module_param(yieldlines, int, 0); module_param(video_nr, int, 0); +/* Set force_init=1 to avoid detection by polling status register and + * immediately attempt to initialize qcam */ +module_param(force_init, int, 0); + static inline int read_lpstatus(struct qcam_device *q) { return parport_read_status(q->pport); @@ -331,6 +336,9 @@ static int qc_detect(struct qcam_device *q) int count = 0; int i; + if (force_init) + return 1; + lastreg = reg = read_lpstatus(q) & 0xf0; for (i = 0; i < 500; i++) @@ -354,12 +362,12 @@ static int qc_detect(struct qcam_device *q) /* Be (even more) liberal in what you accept... */ -/* if (count > 30 && count < 200) */ if (count > 20 && count < 400) { return 1; /* found */ } else { printk(KERN_ERR "No Quickcam found on port %s\n", q->pport->name); + printk(KERN_DEBUG "Quickcam detection counter: %u\n", count); return 0; /* not found */ } } -- 2.39.5