/* * Watchdog driver for DA9063 PMICs. * * Copyright(c) 2012 Dialog Semiconductor Ltd. * * Author: Mariusz Wojtasik * * 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; either version 2 of the License, or (at your * option) any later version. */ #include #include #include #include #include #include #include #include #include #include /* * Watchdog selector to timeout in seconds. * 0: WDT disabled; * others: timeout = 2048 ms * 2^(TWDSCALE-1). */ static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 }; #define DA9063_TWDSCALE_DISABLE 0 #define DA9063_TWDSCALE_MIN 1 #define DA9063_TWDSCALE_MAX (ARRAY_SIZE(wdt_timeout) - 1) #define DA9063_WDT_MIN_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MIN] #define DA9063_WDT_MAX_TIMEOUT wdt_timeout[DA9063_TWDSCALE_MAX] #define DA9063_WDG_TIMEOUT wdt_timeout[3] #define DA9063_RESET_PROTECTION_MS 256 struct da9063_watchdog { struct da9063 *da9063; struct watchdog_device wdtdev; }; static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs) { unsigned int i; for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) { if (wdt_timeout[i] >= secs) return i; } return DA9063_TWDSCALE_MAX; } static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval) { return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D, DA9063_TWDSCALE_MASK, regval); } static int da9063_wdt_start(struct watchdog_device *wdd) { struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); unsigned int selector; int ret; selector = da9063_wdt_timeout_to_sel(wdt->wdtdev.timeout); ret = _da9063_wdt_set_timeout(wdt->da9063, selector); if (ret) dev_err(wdt->da9063->dev, "Watchdog failed to start (err = %d)\n", ret); return ret; } static int da9063_wdt_stop(struct watchdog_device *wdd) { struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); int ret; ret = regmap_update_bits(wdt->da9063->regmap, DA9063_REG_CONTROL_D, DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE); if (ret) dev_alert(wdt->da9063->dev, "Watchdog failed to stop (err = %d)\n", ret); return ret; } static int da9063_wdt_ping(struct watchdog_device *wdd) { struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); int ret; ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F, DA9063_WATCHDOG); if (ret) dev_alert(wdt->da9063->dev, "Failed to ping the watchdog (err = %d)\n", ret); return ret; } static int da9063_wdt_set_timeout(struct watchdog_device *wdd, unsigned int timeout) { struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); unsigned int selector; int ret; selector = da9063_wdt_timeout_to_sel(timeout); ret = _da9063_wdt_set_timeout(wdt->da9063, selector); if (ret) dev_err(wdt->da9063->dev, "Failed to set watchdog timeout (err = %d)\n", ret); else wdd->timeout = wdt_timeout[selector]; return ret; } static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action, void *data) { struct da9063_watchdog *wdt = watchdog_get_drvdata(wdd); int ret; ret = regmap_write(wdt->da9063->regmap, DA9063_REG_CONTROL_F, DA9063_SHUTDOWN); if (ret) dev_alert(wdt->da9063->dev, "Failed to shutdown (err = %d)\n", ret); return ret; } static const struct watchdog_info da9063_watchdog_info = { .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, .identity = "DA9063 Watchdog", }; static const struct watchdog_ops da9063_watchdog_ops = { .owner = THIS_MODULE, .start = da9063_wdt_start, .stop = da9063_wdt_stop, .ping = da9063_wdt_ping, .set_timeout = da9063_wdt_set_timeout, .restart = da9063_wdt_restart, }; static int da9063_wdt_probe(struct platform_device *pdev) { int ret; struct da9063 *da9063; struct da9063_watchdog *wdt; if (!pdev->dev.parent) return -EINVAL; da9063 = dev_get_drvdata(pdev->dev.parent); if (!da9063) return -EINVAL; wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); if (!wdt) return -ENOMEM; wdt->da9063 = da9063; wdt->wdtdev.info = &da9063_watchdog_info; wdt->wdtdev.ops = &da9063_watchdog_ops; wdt->wdtdev.min_timeout = DA9063_WDT_MIN_TIMEOUT; wdt->wdtdev.max_timeout = DA9063_WDT_MAX_TIMEOUT; wdt->wdtdev.min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS; wdt->wdtdev.timeout = DA9063_WDG_TIMEOUT; wdt->wdtdev.parent = &pdev->dev; wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; watchdog_set_restart_priority(&wdt->wdtdev, 128); watchdog_set_drvdata(&wdt->wdtdev, wdt); dev_set_drvdata(&pdev->dev, wdt); ret = watchdog_register_device(&wdt->wdtdev); if (ret) return ret; return 0; } static int da9063_wdt_remove(struct platform_device *pdev) { struct da9063_watchdog *wdt = dev_get_drvdata(&pdev->dev); watchdog_unregister_device(&wdt->wdtdev); return 0; } static struct platform_driver da9063_wdt_driver = { .probe = da9063_wdt_probe, .remove = da9063_wdt_remove, .driver = { .name = DA9063_DRVNAME_WATCHDOG, }, }; module_platform_driver(da9063_wdt_driver); MODULE_AUTHOR("Mariusz Wojtasik "); MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG); 966d79d4c6529a5f7b9206e405'>2c5d9555d6d937966d79d4c6529a5f7b9206e405 (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/net/gre.h')