/* Copyright (c) 2010, 2014 The Linux Foundation. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and * only version 2 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. */ #include #include #include #include "hvc_console.h" /* DCC Status Bits */ #define DCC_STATUS_RX (1 << 30) #define DCC_STATUS_TX (1 << 29) static int hvc_dcc_put_chars(uint32_t vt, const char *buf, int count) { int i; for (i = 0; i < count; i++) { while (__dcc_getstatus() & DCC_STATUS_TX) cpu_relax(); __dcc_putchar(buf[i]); } return count; } static int hvc_dcc_get_chars(uint32_t vt, char *buf, int count) { int i; for (i = 0; i < count; ++i) if (__dcc_getstatus() & DCC_STATUS_RX) buf[i] = __dcc_getchar(); else break; return i; } static bool hvc_dcc_check(void) { unsigned long time = jiffies + (HZ / 10); /* Write a test character to check if it is handled */ __dcc_putchar('\n'); while (time_is_after_jiffies(time)) { if (!(__dcc_getstatus() & DCC_STATUS_TX)) return true; } return false; } static const struct hv_ops hvc_dcc_get_put_ops = { .get_chars = hvc_dcc_get_chars, .put_chars = hvc_dcc_put_chars, }; static int __init hvc_dcc_console_init(void) { int ret; if (!hvc_dcc_check()) return -ENODEV; /* Returns -1 if error */ ret = hvc_instantiate(0, 0, &hvc_dcc_get_put_ops); return ret < 0 ? -ENODEV : 0; } console_initcall(hvc_dcc_console_init); static int __init hvc_dcc_init(void) { struct hvc_struct *p; if (!hvc_dcc_check()) return -ENODEV; p = hvc_alloc(0, 0, &hvc_dcc_get_put_ops, 128); return PTR_ERR_OR_ZERO(p); } device_initcall(hvc_dcc_init); 6369810654df4ee1837566'>commitdiff
path: root/drivers/usb/host/uhci-hcd.c
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authorRicardo Ribalda <ricardo.ribalda@gmail.com>2017-02-02 20:15:16 +0100
committerWolfram Sang <wsa@the-dreams.de>2017-02-09 17:13:01 +0100
commitbbb27fc33d44e7b8d96369810654df4ee1837566 (patch)
treeb769e165ad52c0021054f1a048b62bd7e4fbec47 /drivers/usb/host/uhci-hcd.c
parentf43128c75202f29ee71aa83e6c320a911137c189 (diff)
i2c: piix4: Request the SMBUS semaphore inside the mutex
SMBSLVCNT must be protected with the piix4_mutex_sb800 in order to avoid multiple buses accessing to the semaphore at the same time. Fixes: 701dc207bf55 ("i2c: piix4: Avoid race conditions with IMC") Reported-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/usb/host/uhci-hcd.c')