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| author | iedowse <iedowse@FreeBSD.org> | 2002-10-30 01:18:58 +0000 |
|---|---|---|
| committer | iedowse <iedowse@FreeBSD.org> | 2002-10-30 01:18:58 +0000 |
| commit | 792310e7697ae9822b86915ae13160cb53dd1f23 (patch) | |
| tree | 3f354ffeb9a09a8ee03f78caac1f8289faf9f468 /sys | |
| parent | c98f436d671549d7b42411fc962f851659e903c6 (diff) | |
| download | FreeBSD-src-792310e7697ae9822b86915ae13160cb53dd1f23.zip FreeBSD-src-792310e7697ae9822b86915ae13160cb53dd1f23.tar.gz | |
Check for errors and zero-length transfers in the ulpt_input() input
pipe callback function, and just return if these cases are detected.
Without these checks, the ulpt driver may cause an infinite loop
of failing USB transfers that can hang the whole machine. This makes
printing work for me on a HP DJ950C printer.
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/dev/usb/ulpt.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/sys/dev/usb/ulpt.c b/sys/dev/usb/ulpt.c index 3494d07..b2640f4 100644 --- a/sys/dev/usb/ulpt.c +++ b/sys/dev/usb/ulpt.c @@ -471,6 +471,12 @@ static void ulpt_input(usbd_xfer_handle xfer, usbd_private_handle priv, usbd_status status) { struct ulpt_softc *sc = priv; + u_int32_t count; + + /* Don't loop on errors or 0-length input. */ + usbd_get_xfer_status(xfer, NULL, NULL, &count, NULL); + if (status != USBD_NORMAL_COMPLETION || count == 0) + return; DPRINTFN(2,("ulpt_input: got some data\n")); /* Do it again. */ |
