/* * drivers/tty/serial/8250/8250_pxa.c -- driver for PXA on-board UARTS * Copyright: (C) 2013 Sergei Ianovich * * replaces drivers/serial/pxa.c by Nicolas Pitre * Created: Feb 20, 2003 * Copyright: (C) 2003 Monta Vista Software, Inc. * * Based on drivers/serial/8250.c by Russell King. * * 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 #include #include #include #include #include "8250.h" struct pxa8250_data { int line; struct clk *clk; }; static int __maybe_unused serial_pxa_suspend(struct device *dev) { struct pxa8250_data *data = dev_get_drvdata(dev); serial8250_suspend_port(data->line); return 0; } static int __maybe_unused serial_pxa_resume(struct device *dev) { struct pxa8250_data *data = dev_get_drvdata(dev); serial8250_resume_port(data->line); return 0; } static const struct dev_pm_ops serial_pxa_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(serial_pxa_suspend, serial_pxa_resume) }; static const struct of_device_id serial_pxa_dt_ids[] = { { .compatible = "mrvl,pxa-uart", }, { .compatible = "mrvl,mmp-uart", }, {} }; MODULE_DEVICE_TABLE(of, serial_pxa_dt_ids); /* Uart divisor latch write */ static void serial_pxa_dl_write(struct uart_8250_port *up, int value) { unsigned int dll; serial_out(up, UART_DLL, value & 0xff); /* * work around Erratum #74 according to Marvel(R) PXA270M Processor * Specification Update (April 19, 2010) */ dll = serial_in(up, UART_DLL); WARN_ON(dll != (value & 0xff)); serial_out(up, UART_DLM, value >> 8 & 0xff); } static void serial_pxa_pm(struct uart_port *port, unsigned int state, unsigned int oldstate) { struct pxa8250_data *data = port->private_data; if (!state) clk_prepare_enable(data->clk); else clk_disable_unprepare(data->clk); } static int serial_pxa_probe(struct platform_device *pdev) { struct uart_8250_port uart = {}; struct pxa8250_data *data; struct resource *mmres, *irqres; int ret; mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0); irqres = platform_get_resource(pdev, IORESOURCE_IRQ, 0); if (!mmres || !irqres) return -ENODEV; data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; data->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(data->clk)) return PTR_ERR(data->clk); ret = clk_prepare(data->clk); if (ret) return ret; uart.port.type = PORT_XSCALE; uart.port.iotype = UPIO_MEM32; uart.port.mapbase = mmres->start; uart.port.regshift = 2; uart.port.irq = irqres->start; uart.port.fifosize = 64; uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST; uart.port.dev = &pdev->dev; uart.port.uartclk = clk_get_rate(data->clk); uart.port.pm = serial_pxa_pm; uart.port.private_data = data; uart.dl_write = serial_pxa_dl_write; ret = serial8250_register_8250_port(&uart); if (ret < 0) goto err_clk; data->line = ret; platform_set_drvdata(pdev, data); return 0; err_clk: clk_unprepare(data->clk); return ret; } static int serial_pxa_remove(struct platform_device *pdev) { struct pxa8250_data *data = platform_get_drvdata(pdev); serial8250_unregister_port(data->line); clk_unprepare(data->clk); return 0; } static struct platform_driver serial_pxa_driver = { .probe = serial_pxa_probe, .remove = serial_pxa_remove, .driver = { .name = "pxa2xx-uart", .pm = &serial_pxa_pm_ops, .of_match_table = serial_pxa_dt_ids, }, }; module_platform_driver(serial_pxa_driver); #ifdef CONFIG_SERIAL_8250_CONSOLE static int __init early_serial_pxa_setup(struct earlycon_device *device, const char *options) { struct uart_port *port = &device->port; if (!(device->port.membase || device->port.iobase)) return -ENODEV; port->regshift = 2; return early_serial8250_setup(device, NULL); } OF_EARLYCON_DECLARE(early_pxa, "mrvl,pxa-uart", early_serial_pxa_setup); #endif MODULE_AUTHOR("Sergei Ianovich"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:pxa2xx-uart"); s.form.submit();'>
authorLinus Torvalds <torvalds@linux-foundation.org>2017-01-29 13:50:06 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-29 13:50:06 -0800
commit39cb2c9a316e77f6dfba96c543e55b6672d5a37e (patch)
tree98fe974ee4e20121253de7f61fc8d01bdb3821c1 /include/dt-bindings/clock/gxbb-clkc.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/gxbb-clkc.h')