/**************************************************************************** Copyright Echo Digital Audio Corporation (c) 1998 - 2004 All rights reserved www.echoaudio.com This file is part of Echo Digital Audio's generic driver library. Echo Digital Audio's generic driver library 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. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. ************************************************************************* Translation from C++ and adaptation for use in ALSA-Driver were made by Giuliano Pochini ****************************************************************************/ static int set_vmixer_gain(struct echoaudio *chip, u16 output, u16 pipe, int gain); static int update_vmixer_level(struct echoaudio *chip); static int init_hw(struct echoaudio *chip, u16 device_id, u16 subdevice_id) { int err; if (snd_BUG_ON((subdevice_id & 0xfff0) != INDIGO_DJ)) return -ENODEV; if ((err = init_dsp_comm_page(chip))) { dev_err(chip->card->dev, "init_hw - could not initialize DSP comm page\n"); return err; } chip->device_id = device_id; chip->subdevice_id = subdevice_id; chip->bad_board = true; chip->dsp_code_to_load = FW_INDIGO_DJ_DSP; /* Since this card has no ASIC, mark it as loaded so everything works OK */ chip->asic_loaded = true; chip->input_clock_types = ECHO_CLOCK_BIT_INTERNAL; if ((err = load_firmware(chip)) < 0) return err; chip->bad_board = false; return err; } static int set_mixer_defaults(struct echoaudio *chip) { return init_line_levels(chip); } static u32 detect_input_clocks(const struct echoaudio *chip) { return ECHO_CLOCK_BIT_INTERNAL; } /* The IndigoDJ has no ASIC. Just do nothing */ static int load_asic(struct echoaudio *chip) { return 0; } static int set_sample_rate(struct echoaudio *chip, u32 rate) { u32 control_reg; switch (rate) { case 96000: control_reg = MIA_96000; break; case 88200: control_reg = MIA_88200; break; case 48000: control_reg = MIA_48000; break; case 44100: control_reg = MIA_44100; break; case 32000: control_reg = MIA_32000; break; default: dev_err(chip->card->dev, "set_sample_rate: %d invalid!\n", rate); return -EINVAL; } /* Set the control register if it has changed */ if (control_reg != le32_to_cpu(chip->comm_page->control_register)) { if (wait_handshake(chip)) return -EIO; chip->comm_page->sample_rate = cpu_to_le32(rate); /* ignored by the DSP */ chip->comm_page->control_register = cpu_to_le32(control_reg); chip->sample_rate = rate; clear_handshake(chip); return send_vector(chip, DSP_VC_UPDATE_CLOCKS); } return 0; } /* This function routes the sound from a virtual channel to a real output */ static int set_vmixer_gain(struct echoaudio *chip, u16 output, u16 pipe, int gain) { int index; if (snd_BUG_ON(pipe >= num_pipes_out(chip) || output >= num_busses_out(chip))) return -EINVAL; if (wait_handshake(chip)) return -EIO; chip->vmixer_gain[output][pipe] = gain; index = output * num_pipes_out(chip) + pipe; chip->comm_page->vmixer[index] = gain; dev_dbg(chip->card->dev, "set_vmixer_gain: pipe %d, out %d = %d\n", pipe, output, gain); return 0; } /* Tell the DSP to read and update virtual mixer levels in comm page. */ static int update_vmixer_level(struct echoaudio *chip) { if (wait_handshake(chip)) return -EIO; clear_handshake(chip); return send_vector(chip, DSP_VC_SET_VMIXER_GAIN); } tion>space:mode:
authorJohn Brooks <john@fastquake.com>2017-01-18 21:50:39 +0000
committerJonathan Cameron <jic23@kernel.org>2017-01-22 13:35:40 +0000
commit5c113b5e0082e90d2e1c7b12e96a7b8cf0623e27 (patch)
treecaf374a799c6c5f8bdf865d7fc0e936e9685f4ca /drivers/usb/host/ehci-hcd.c
parentd1aaf20ee655888c227d5137b7a63551f8d15416 (diff)
iio: dht11: Use usleep_range instead of msleep for start signal
The DHT22 (AM2302) datasheet specifies that the LOW start pulse should not exceed 20ms. However, observations with an oscilloscope of an RPi Model 2B (rev 1.1) communicating with a DHT22 sensor showed that the driver was consistently sending start pulses longer than 20ms: Kernel 4.7.10-v7+ (n=132): Minimum pulse length: 20.20ms Maximum: 29.84ms Mean: 24.96ms StDev: 2.82ms Sensor response rate: 100% Read success rate: 76% On kernel 4.8, the start pulse was so long that the sensor would not even respond 97% of the time: Kernel 4.8.16-v7+ (n=100): Minimum pulse length: 30.4ms Maximum: 74.4ms Mean: 39.3ms StDev: 10.2ms Sensor response rate: 3% Read success rate: 3% The driver would return ETIMEDOUT and write log messages like this: [ 51.430987] dht11 dht11@0: Only 1 signal edges detected [ 66.311019] dht11 dht11@0: Only 0 signal edges detected Replacing msleep(18) with usleep_range(18000, 20000) made the pulse length sane again and restored responsiveness: Kernel 4.8.16-v7+ with usleep_range (n=123): Minimum pulse length: 18.16ms Maximum: 20.20ms Mean: 19.85ms StDev: 0.51ms Sensor response rate: 100% Read success rate: 84% Cc: stable@vger.kernel.org Signed-off-by: John Brooks <john@fastquake.com> Reviewed-by: Harald Geyer <harald@ccbib.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers/usb/host/ehci-hcd.c')