1 // SPDX-License-Identifier: MIT 2 /* 3 * Copyright © 2019 Intel Corporation 4 */ 5 6 #include <drm/drm_drv.h> 7 8 #include "i915_drv.h" 9 #include "i915_utils.h" 10 11 #define FDO_BUG_URL "https://bugs.freedesktop.org/enter_bug.cgi?product=DRI" 12 #define FDO_BUG_MSG "Please file a bug at " FDO_BUG_URL " against DRM/Intel " \ 13 "providing the dmesg log by booting with drm.debug=0xf" 14 15 void 16 __i915_printk(struct drm_i915_private *dev_priv, const char *level, 17 const char *fmt, ...) 18 { 19 static bool shown_bug_once; 20 struct device *kdev = dev_priv->drm.dev; 21 bool is_error = level[1] <= KERN_ERR[1]; 22 bool is_debug = level[1] == KERN_DEBUG[1]; 23 struct va_format vaf; 24 va_list args; 25 26 if (is_debug && !drm_debug_enabled(DRM_UT_DRIVER)) 27 return; 28 29 va_start(args, fmt); 30 31 vaf.fmt = fmt; 32 vaf.va = &args; 33 34 if (is_error) 35 dev_printk(level, kdev, "%pV", &vaf); 36 else 37 dev_printk(level, kdev, "[" DRM_NAME ":%ps] %pV", 38 __builtin_return_address(0), &vaf); 39 40 va_end(args); 41 42 if (is_error && !shown_bug_once) { 43 /* 44 * Ask the user to file a bug report for the error, except 45 * if they may have caused the bug by fiddling with unsafe 46 * module parameters. 47 */ 48 if (!test_taint(TAINT_USER)) 49 dev_notice(kdev, "%s", FDO_BUG_MSG); 50 shown_bug_once = true; 51 } 52 } 53 54 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG) 55 static unsigned int i915_probe_fail_count; 56 57 int __i915_inject_probe_error(struct drm_i915_private *i915, int err, 58 const char *func, int line) 59 { 60 if (i915_probe_fail_count >= i915_modparams.inject_probe_failure) 61 return 0; 62 63 if (++i915_probe_fail_count < i915_modparams.inject_probe_failure) 64 return 0; 65 66 __i915_printk(i915, KERN_INFO, 67 "Injecting failure %d at checkpoint %u [%s:%d]\n", 68 err, i915_modparams.inject_probe_failure, func, line); 69 i915_modparams.inject_probe_failure = 0; 70 return err; 71 } 72 73 bool i915_error_injected(void) 74 { 75 return i915_probe_fail_count && !i915_modparams.inject_probe_failure; 76 } 77 78 #endif 79 80 void cancel_timer(struct timer_list *t) 81 { 82 if (!READ_ONCE(t->expires)) 83 return; 84 85 del_timer(t); 86 WRITE_ONCE(t->expires, 0); 87 } 88 89 void set_timer_ms(struct timer_list *t, unsigned long timeout) 90 { 91 if (!timeout) { 92 cancel_timer(t); 93 return; 94 } 95 96 timeout = msecs_to_jiffies_timeout(timeout); 97 98 /* 99 * Paranoia to make sure the compiler computes the timeout before 100 * loading 'jiffies' as jiffies is volatile and may be updated in 101 * the background by a timer tick. All to reduce the complexity 102 * of the addition and reduce the risk of losing a jiffie. 103 */ 104 barrier(); 105 106 mod_timer(t, jiffies + timeout); 107 } 108