/* * Maxim MAX77620 Watchdog Driver * * Copyright (C) 2016 NVIDIA CORPORATION. All rights reserved. * * Author: Laxman Dewangan * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #include static bool nowayout = WATCHDOG_NOWAYOUT; struct max77620_wdt { struct device *dev; struct regmap *rmap; struct watchdog_device wdt_dev; }; static int max77620_wdt_start(struct watchdog_device *wdt_dev) { struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev); return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2, MAX77620_WDTEN, MAX77620_WDTEN); } static int max77620_wdt_stop(struct watchdog_device *wdt_dev) { struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev); return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2, MAX77620_WDTEN, 0); } static int max77620_wdt_ping(struct watchdog_device *wdt_dev) { struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev); return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL3, MAX77620_WDTC_MASK, 0x1); } static int max77620_wdt_set_timeout(struct watchdog_device *wdt_dev, unsigned int timeout) { struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev); unsigned int wdt_timeout; u8 regval; int ret; switch (timeout) { case 0 ... 2: regval = MAX77620_TWD_2s; wdt_timeout = 2; break; case 3 ... 16: regval = MAX77620_TWD_16s; wdt_timeout = 16; break; case 17 ... 64: regval = MAX77620_TWD_64s; wdt_timeout = 64; break; default: regval = MAX77620_TWD_128s; wdt_timeout = 128; break; } ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL3, MAX77620_WDTC_MASK, 0x1); if (ret < 0) return ret; ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2, MAX77620_TWD_MASK, regval); if (ret < 0) return ret; wdt_dev->timeout = wdt_timeout; return 0; } static const struct watchdog_info max77620_wdt_info = { .identity = "max77620-watchdog", .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, }; static const struct watchdog_ops max77620_wdt_ops = { .start = max77620_wdt_start, .stop = max77620_wdt_stop, .ping = max77620_wdt_ping, .set_timeout = max77620_wdt_set_timeout, }; static int max77620_wdt_probe(struct platform_device *pdev) { struct max77620_wdt *wdt; struct watchdog_device *wdt_dev; unsigned int regval; int ret; wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); if (!wdt) return -ENOMEM; wdt->dev = &pdev->dev; wdt->rmap = dev_get_regmap(pdev->dev.parent, NULL); if (!wdt->rmap) { dev_err(wdt->dev, "Failed to get parent regmap\n"); return -ENODEV; } wdt_dev = &wdt->wdt_dev; wdt_dev->info = &max77620_wdt_info; wdt_dev->ops = &max77620_wdt_ops; wdt_dev->min_timeout = 2; wdt_dev->max_timeout = 128; wdt_dev->max_hw_heartbeat_ms = 128 * 1000; platform_set_drvdata(pdev, wdt); /* Enable WD_RST_WK - WDT expire results in a restart */ ret = regmap_update_bits(wdt->rmap, MAX77620_REG_ONOFFCNFG2, MAX77620_ONOFFCNFG2_WD_RST_WK, MAX77620_ONOFFCNFG2_WD_RST_WK); if (ret < 0) { dev_err(wdt->dev, "Failed to set WD_RST_WK: %d\n", ret); return ret; } /* Set WDT clear in OFF and sleep mode */ ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2, MAX77620_WDTOFFC | MAX77620_WDTSLPC, MAX77620_WDTOFFC | MAX77620_WDTSLPC); if (ret < 0) { dev_err(wdt->dev, "Failed to set WDT OFF mode: %d\n", ret); return ret; } /* Check if WDT running and if yes then set flags properly */ ret = regmap_read(wdt->rmap, MAX77620_REG_CNFGGLBL2, ®val); if (ret < 0) { dev_err(wdt->dev, "Failed to read WDT CFG register: %d\n", ret); return ret; } switch (regval & MAX77620_TWD_MASK) { case MAX77620_TWD_2s: wdt_dev->timeout = 2; break; case MAX77620_TWD_16s: wdt_dev->timeout = 16; break; case MAX77620_TWD_64s: wdt_dev->timeout = 64; break; default: wdt_dev->timeout = 128; break; } if (regval & MAX77620_WDTEN) set_bit(WDOG_HW_RUNNING, &wdt_dev->status); watchdog_set_nowayout(wdt_dev, nowayout); watchdog_set_drvdata(wdt_dev, wdt); ret = watchdog_register_device(wdt_dev); if (ret < 0) { dev_err(&pdev->dev, "watchdog registration failed: %d\n", ret); return ret; } return 0; } static int max77620_wdt_remove(struct platform_device *pdev) { struct max77620_wdt *wdt = platform_get_drvdata(pdev); max77620_wdt_stop(&wdt->wdt_dev); watchdog_unregister_device(&wdt->wdt_dev); return 0; } static struct platform_device_id max77620_wdt_devtype[] = { { .name = "max77620-watchdog", }, { }, }; MODULE_DEVICE_TABLE(platform, max77620_wdt_devtype); static struct platform_driver max77620_wdt_driver = { .driver = { .name = "max77620-watchdog", }, .probe = max77620_wdt_probe, .remove = max77620_wdt_remove, .id_table = max77620_wdt_devtype, }; module_platform_driver(max77620_wdt_driver); MODULE_DESCRIPTION("Max77620 watchdog timer driver"); module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); MODULE_AUTHOR("Laxman Dewangan "); MODULE_LICENSE("GPL v2"); t/tree/?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>98fe974ee4e20121253de7f61fc8d01bdb3821c1 /include/dt-bindings/clock/jz4740-cgu.h parent2c5d9555d6d937966d79d4c6529a5f7b9206e405 (diff)
drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()
I've seen this trigger twice now, where the i915_gem_object_to_ggtt() call in intel_unpin_fb_obj() returns NULL, resulting in an oops immediately afterwards as the (inlined) call to i915_vma_unpin_fence() tries to dereference it. It seems to be some race condition where the object is going away at shutdown time, since both times happened when shutting down the X server. The call chains were different: - VT ioctl(KDSETMODE, KD_TEXT): intel_cleanup_plane_fb+0x5b/0xa0 [i915] drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper] intel_atomic_commit_tail+0x749/0xfe0 [i915] intel_atomic_commit+0x3cb/0x4f0 [i915] drm_atomic_commit+0x4b/0x50 [drm] restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper] drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper] drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper] intel_fbdev_set_par+0x18/0x70 [i915] fb_set_var+0x236/0x460 fbcon_blank+0x30f/0x350 do_unblank_screen+0xd2/0x1a0 vt_ioctl+0x507/0x12a0 tty_ioctl+0x355/0xc30 do_vfs_ioctl+0xa3/0x5e0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x13/0x94 - i915 unpin_work workqueue: intel_unpin_work_fn+0x58/0x140 [i915] process_one_work+0x1f1/0x480 worker_thread+0x48/0x4d0 kthread+0x101/0x140 and this patch purely papers over 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 'include/dt-bindings/clock/jz4740-cgu.h')