/* * Copyright (C) 2009-2010, Lars-Peter Clausen * PCF50633 backlight device driver * * 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. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include #include #include #include #include #include #include #include struct pcf50633_bl { struct pcf50633 *pcf; struct backlight_device *bl; unsigned int brightness; unsigned int brightness_limit; }; /* * pcf50633_bl_set_brightness_limit * * Update the brightness limit for the pc50633 backlight. The actual brightness * will not go above the limit. This is useful to limit power drain for example * on low battery. * * @dev: Pointer to a pcf50633 device * @limit: The brightness limit. Valid values are 0-63 */ int pcf50633_bl_set_brightness_limit(struct pcf50633 *pcf, unsigned int limit) { struct pcf50633_bl *pcf_bl = platform_get_drvdata(pcf->bl_pdev); if (!pcf_bl) return -ENODEV; pcf_bl->brightness_limit = limit & 0x3f; backlight_update_status(pcf_bl->bl); return 0; } static int pcf50633_bl_update_status(struct backlight_device *bl) { struct pcf50633_bl *pcf_bl = bl_get_data(bl); unsigned int new_brightness; if (bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK) || bl->props.power != FB_BLANK_UNBLANK) new_brightness = 0; else if (bl->props.brightness < pcf_bl->brightness_limit) new_brightness = bl->props.brightness; else new_brightness = pcf_bl->brightness_limit; if (pcf_bl->brightness == new_brightness) return 0; if (new_brightness) { pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDOUT, new_brightness); if (!pcf_bl->brightness) pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDENA, 1); } else { pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDENA, 0); } pcf_bl->brightness = new_brightness; return 0; } static int pcf50633_bl_get_brightness(struct backlight_device *bl) { struct pcf50633_bl *pcf_bl = bl_get_data(bl); return pcf_bl->brightness; } static const struct backlight_ops pcf50633_bl_ops = { .get_brightness = pcf50633_bl_get_brightness, .update_status = pcf50633_bl_update_status, .options = BL_CORE_SUSPENDRESUME, }; static int pcf50633_bl_probe(struct platform_device *pdev) { struct pcf50633_bl *pcf_bl; struct device *parent = pdev->dev.parent; struct pcf50633_platform_data *pcf50633_data = dev_get_platdata(parent); struct pcf50633_bl_platform_data *pdata = pcf50633_data->backlight_data; struct backlight_properties bl_props; pcf_bl = devm_kzalloc(&pdev->dev, sizeof(*pcf_bl), GFP_KERNEL); if (!pcf_bl) return -ENOMEM; memset(&bl_props, 0, sizeof(bl_props)); bl_props.type = BACKLIGHT_RAW; bl_props.max_brightness = 0x3f; bl_props.power = FB_BLANK_UNBLANK; if (pdata) { bl_props.brightness = pdata->default_brightness; pcf_bl->brightness_limit = pdata->default_brightness_limit; } else { bl_props.brightness = 0x3f; pcf_bl->brightness_limit = 0x3f; } pcf_bl->pcf = dev_to_pcf50633(pdev->dev.parent); pcf_bl->bl = devm_backlight_device_register(&pdev->dev, pdev->name, &pdev->dev, pcf_bl, &pcf50633_bl_ops, &bl_props); if (IS_ERR(pcf_bl->bl)) return PTR_ERR(pcf_bl->bl); platform_set_drvdata(pdev, pcf_bl); pcf50633_reg_write(pcf_bl->pcf, PCF50633_REG_LEDDIM, pdata->ramp_time); /* * Should be different from bl_props.brightness, so we do not exit * update_status early the first time it's called */ pcf_bl->brightness = pcf_bl->bl->props.brightness + 1; backlight_update_status(pcf_bl->bl); return 0; } static struct platform_driver pcf50633_bl_driver = { .probe = pcf50633_bl_probe, .driver = { .name = "pcf50633-backlight", }, }; module_platform_driver(pcf50633_bl_driver); MODULE_AUTHOR("Lars-Peter Clausen "); MODULE_DESCRIPTION("PCF50633 backlight driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:pcf50633-backlight"); class='ctrl'>mode:
authorBjorn Helgaas <bhelgaas@google.com>2017-01-27 15:00:45 -0600
committerBjorn Helgaas <bhelgaas@google.com>2017-01-27 15:00:45 -0600
commit030305d69fc6963c16003f50d7e8d74b02d0a143 (patch)
tree363a4e34d199178769b7e7eeb26ea2620a55847b /tools/testing/selftests/vm/compaction_test.c
parent4d191b1b63c209e37bf27938ef365244d3c41084 (diff)
PCI/ASPM: Handle PCI-to-PCIe bridges as roots of PCIe hierarchies
In a struct pcie_link_state, link->root points to the pcie_link_state of the root of the PCIe hierarchy. For the topmost link, this points to itself (link->root = link). For others, we copy the pointer from the parent (link->root = link->parent->root). Previously we recognized that Root Ports originated PCIe hierarchies, but we treated PCI/PCI-X to PCIe Bridges as being in the middle of the hierarchy, and when we tried to copy the pointer from link->parent->root, there was no parent, and we dereferenced a NULL pointer: BUG: unable to handle kernel NULL pointer dereference at 0000000000000090 IP: [<ffffffff9e424350>] pcie_aspm_init_link_state+0x170/0x820 Recognize that PCI/PCI-X to PCIe Bridges originate PCIe hierarchies just like Root Ports do, so link->root for these devices should also point to itself. Fixes: 51ebfc92b72b ("PCI: Enumerate switches below PCI-to-PCIe bridges") Link: https://bugzilla.kernel.org/show_bug.cgi?id=193411 Link: https://bugzilla.opensuse.org/show_bug.cgi?id=1022181 Tested-by: lists@ssl-mail.com Tested-by: Jayachandran C. <jnair@caviumnetworks.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v4.2+
Diffstat (limited to 'tools/testing/selftests/vm/compaction_test.c')