/* * Line 6 Linux USB driver * * Copyright (C) 2004-2010 Markus Grabner (grabner@icg.tugraz.at) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation, version 2. * */ #include #include #include #include #include #include "driver.h" #include "midi.h" #define line6_rawmidi_substream_midi(substream) \ ((struct snd_line6_midi *)((substream)->rmidi->private_data)) static int send_midi_async(struct usb_line6 *line6, unsigned char *data, int length); /* Pass data received via USB to MIDI. */ void line6_midi_receive(struct usb_line6 *line6, unsigned char *data, int length) { if (line6->line6midi->substream_receive) snd_rawmidi_receive(line6->line6midi->substream_receive, data, length); } /* Read data from MIDI buffer and transmit them via USB. */ static void line6_midi_transmit(struct snd_rawmidi_substream *substream) { struct usb_line6 *line6 = line6_rawmidi_substream_midi(substream)->line6; struct snd_line6_midi *line6midi = line6->line6midi; struct midi_buffer *mb = &line6midi->midibuf_out; unsigned char chunk[LINE6_FALLBACK_MAXPACKETSIZE]; int req, done; for (;;) { req = min(line6_midibuf_bytes_free(mb), line6->max_packet_size); done = snd_rawmidi_transmit_peek(substream, chunk, req); if (done == 0) break; line6_midibuf_write(mb, chunk, done); snd_rawmidi_transmit_ack(substream, done); } for (;;) { done = line6_midibuf_read(mb, chunk, LINE6_FALLBACK_MAXPACKETSIZE); if (done == 0) break; send_midi_async(line6, chunk, done); } } /* Notification of completion of MIDI transmission. */ static void midi_sent(struct urb *urb) { unsigned long flags; int status; int num; struct usb_line6 *line6 = (struct usb_line6 *)urb->context; status = urb->status; kfree(urb->transfer_buffer); usb_free_urb(urb); if (status == -ESHUTDOWN) return; spin_lock_irqsave(&line6->line6midi->lock, flags); num = --line6->line6midi->num_active_send_urbs; if (num == 0) { line6_midi_transmit(line6->line6midi->substream_transmit); num = line6->line6midi->num_active_send_urbs; } if (num == 0) wake_up(&line6->line6midi->send_wait); spin_unlock_irqrestore(&line6->line6midi->lock, flags); } /* Send an asynchronous MIDI message. Assumes that line6->line6midi->lock is held (i.e., this function is serialized). */ static int send_midi_async(struct usb_line6 *line6, unsigned char *data, int length) { struct urb *urb; int retval; unsigned char *transfer_buffer; urb = usb_alloc_urb(0, GFP_ATOMIC); if (urb == NULL) return -ENOMEM; transfer_buffer = kmemdup(data, length, GFP_ATOMIC); if (transfer_buffer == NULL) { usb_free_urb(urb); return -ENOMEM; } usb_fill_int_urb(urb, line6->usbdev, usb_sndbulkpipe(line6->usbdev, line6->properties->ep_ctrl_w), transfer_buffer, length, midi_sent, line6, line6->interval); urb->actual_length = 0; retval = usb_submit_urb(urb, GFP_ATOMIC); if (retval < 0) { dev_err(line6->ifcdev, "usb_submit_urb failed\n"); usb_free_urb(urb); return retval; } ++line6->line6midi->num_active_send_urbs; return 0; } static int line6_midi_output_open(struct snd_rawmidi_substream *substream) { return 0; } static int line6_midi_output_close(struct snd_rawmidi_substream *substream) { return 0; } static void line6_midi_output_trigger(struct snd_rawmidi_substream *substream, int up) { unsigned long flags; struct usb_line6 *line6 = line6_rawmidi_substream_midi(substream)->line6; line6->line6midi->substream_transmit = substream; spin_lock_irqsave(&line6->line6midi->lock, flags); if (line6->line6midi->num_active_send_urbs == 0) line6_midi_transmit(substream); spin_unlock_irqrestore(&line6->line6midi->lock, flags); } static void line6_midi_output_drain(struct snd_rawmidi_substream *substream) { struct usb_line6 *line6 = line6_rawmidi_substream_midi(substream)->line6; struct snd_line6_midi *midi = line6->line6midi; wait_event_interruptible(midi->send_wait, midi->num_active_send_urbs == 0); } static int line6_midi_input_open(struct snd_rawmidi_substream *substream) { return 0; } static int line6_midi_input_close(struct snd_rawmidi_substream *substream) { return 0; } static void line6_midi_input_trigger(struct snd_rawmidi_substream *substream, int up) { struct usb_line6 *line6 = line6_rawmidi_substream_midi(substream)->line6; if (up) line6->line6midi->substream_receive = substream; else line6->line6midi->substream_receive = NULL; } static struct snd_rawmidi_ops line6_midi_output_ops = { .open = line6_midi_output_open, .close = line6_midi_output_close, .trigger = line6_midi_output_trigger, .drain = line6_midi_output_drain, }; static struct snd_rawmidi_ops line6_midi_input_ops = { .open = line6_midi_input_open, .close = line6_midi_input_close, .trigger = line6_midi_input_trigger, }; /* Create a MIDI device */ static int snd_line6_new_midi(struct usb_line6 *line6, struct snd_rawmidi **rmidi_ret) { struct snd_rawmidi *rmidi; int err; err = snd_rawmidi_new(line6->card, "Line 6 MIDI", 0, 1, 1, rmidi_ret); if (err < 0) return err; rmidi = *rmidi_ret; strcpy(rmidi->id, line6->properties->id); strcpy(rmidi->name, line6->properties->name); rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT | SNDRV_RAWMIDI_INFO_INPUT | SNDRV_RAWMIDI_INFO_DUPLEX; snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &line6_midi_output_ops); snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &line6_midi_input_ops); return 0; } /* MIDI device destructor */ static void snd_line6_midi_free(struct snd_rawmidi *rmidi) { struct snd_line6_midi *line6midi = rmidi->private_data; line6_midibuf_destroy(&line6midi->midibuf_in); line6_midibuf_destroy(&line6midi->midibuf_out); kfree(line6midi); } /* Initialize the Line 6 MIDI subsystem. */ int line6_init_midi(struct usb_line6 *line6) { int err; struct snd_rawmidi *rmidi; struct snd_line6_midi *line6midi; if (!(line6->properties->capabilities & LINE6_CAP_CONTROL_MIDI)) { /* skip MIDI initialization and report success */ return 0; } err = snd_line6_new_midi(line6, &rmidi); if (err < 0) return err; line6midi = kzalloc(sizeof(struct snd_line6_midi), GFP_KERNEL); if (!line6midi) return -ENOMEM; rmidi->private_data = line6midi; rmidi->private_free = snd_line6_midi_free; init_waitqueue_head(&line6midi->send_wait); spin_lock_init(&line6midi->lock); line6midi->line6 = line6; err = line6_midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0); if (err < 0) return err; err = line6_midibuf_init(&line6midi->midibuf_out, MIDI_BUFFER_SIZE, 1); if (err < 0) return err; line6->line6midi = line6midi; return 0; } EXPORT_SYMBOL_GPL(line6_init_midi); er the issue by adding a NULL pointer check and a WARN_ON_ONCE() to avoid the oops that would then generally make the machine unresponsive. Other callers of i915_gem_object_to_ggtt() seem to also check for the returned pointer being NULL and warn about it, so this clearly has happened before in other places. [ Reported it originally to the i915 developers on Jan 8, applying the ugly workaround on my own now after triggering the problem for the second time with no feedback. This is likely to be the same bug reported as https://bugs.freedesktop.org/show_bug.cgi?id=98829 https://bugs.freedesktop.org/show_bug.cgi?id=99134 which has a patch for the underlying problem, but it hasn't gotten to me, so I'm applying the workaround. ] Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'net/9p')