From 145b3fe579db66fbe999a2bc3fd5b63dffe9636d Mon Sep 17 00:00:00 2001 From: Ricardo Ribalda Delgado Date: Tue, 2 Dec 2014 17:35:04 +0100 Subject: [PATCH 01/10] PCI: Generate uppercase hex for modalias var in uevent Some implementations of modprobe fail to load the driver for a PCI device automatically because the "interface" part of the modalias from the kernel is lowercase, and the modalias from file2alias is uppercase. The "interface" is the low-order byte of the Class Code, defined in PCI r3.0, Appendix D. Most interface types defined in the spec do not use alpha characters, so they won't be affected. For example, 00h, 01h, 10h, 20h, etc. are unaffected. Print the "interface" byte of the Class Code in uppercase hex, as we already do for the Vendor ID, Device ID, Class, etc. Commit 89ec3dcf17fd ("PCI: Generate uppercase hex for modalias interface class") fixed only half of the problem. Some udev implementations rely on the uevent file and not the modalias file. Fixes: d1ded203adf1 ("PCI: add MODALIAS to hotplug event for pci devices") Fixes: 89ec3dcf17fd ("PCI: Generate uppercase hex for modalias interface class") Signed-off-by: Ricardo Ribalda Delgado Signed-off-by: Bjorn Helgaas Acked-by: Greg Kroah-Hartman CC: stable@vger.kernel.org --- drivers/pci/pci-driver.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 887e6bd95af7..09a66bad8018 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -1383,7 +1383,7 @@ static int pci_uevent(struct device *dev, struct kobj_uevent_env *env) if (add_uevent_var(env, "PCI_SLOT_NAME=%s", pci_name(pdev))) return -ENOMEM; - if (add_uevent_var(env, "MODALIAS=pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02x", + if (add_uevent_var(env, "MODALIAS=pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02X", pdev->vendor, pdev->device, pdev->subsystem_vendor, pdev->subsystem_device, (u8)(pdev->class >> 16), (u8)(pdev->class >> 8), From f331a859e0ee5a898c1f47596eddad4c4f02d657 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Thu, 15 Jan 2015 18:16:04 -0600 Subject: [PATCH 02/10] PCI: Add flag for devices where we can't use bus reset Enable a mechanism for devices to quirk that they do not behave when doing a PCI bus reset. We require a modest level of spec compliant behavior in order to do a reset, for instance the device should come out of reset without throwing errors and PCI config space should be accessible after reset. This is too much to ask for some devices. Link: http://lkml.kernel.org/r/20140923210318.498dacbd@dualc.maya.org Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas CC: stable@vger.kernel.org # v3.14+ --- drivers/pci/pci.c | 40 ++++++++++++++++++++++++++++++++++++---- include/linux/pci.h | 2 ++ 2 files changed, 38 insertions(+), 4 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index cab05f31223f..e9d4fd861ba1 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3271,7 +3271,8 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe) { struct pci_dev *pdev; - if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self) + if (pci_is_root_bus(dev->bus) || dev->subordinate || + !dev->bus->self || dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET) return -ENOTTY; list_for_each_entry(pdev, &dev->bus->devices, bus_list) @@ -3305,7 +3306,8 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) { struct pci_dev *pdev; - if (dev->subordinate || !dev->slot) + if (dev->subordinate || !dev->slot || + dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET) return -ENOTTY; list_for_each_entry(pdev, &dev->bus->devices, bus_list) @@ -3557,6 +3559,20 @@ int pci_try_reset_function(struct pci_dev *dev) } EXPORT_SYMBOL_GPL(pci_try_reset_function); +/* Do any devices on or below this bus prevent a bus reset? */ +static bool pci_bus_resetable(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET || + (dev->subordinate && !pci_bus_resetable(dev->subordinate))) + return false; + } + + return true; +} + /* Lock devices from the top of the tree down */ static void pci_bus_lock(struct pci_bus *bus) { @@ -3607,6 +3623,22 @@ unlock: return 0; } +/* Do any devices on or below this slot prevent a bus reset? */ +static bool pci_slot_resetable(struct pci_slot *slot) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &slot->bus->devices, bus_list) { + if (!dev->slot || dev->slot != slot) + continue; + if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET || + (dev->subordinate && !pci_bus_resetable(dev->subordinate))) + return false; + } + + return true; +} + /* Lock devices from the top of the tree down */ static void pci_slot_lock(struct pci_slot *slot) { @@ -3728,7 +3760,7 @@ static int pci_slot_reset(struct pci_slot *slot, int probe) { int rc; - if (!slot) + if (!slot || !pci_slot_resetable(slot)) return -ENOTTY; if (!probe) @@ -3820,7 +3852,7 @@ EXPORT_SYMBOL_GPL(pci_try_reset_slot); static int pci_bus_reset(struct pci_bus *bus, int probe) { - if (!bus->self) + if (!bus->self || !pci_bus_resetable(bus)) return -ENOTTY; if (probe) diff --git a/include/linux/pci.h b/include/linux/pci.h index 360a966a97a5..44627f1df4ca 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -175,6 +175,8 @@ enum pci_dev_flags { PCI_DEV_FLAGS_DMA_ALIAS_DEVFN = (__force pci_dev_flags_t) (1 << 4), /* Use a PCIe-to-PCI bridge alias even if !pci_is_pcie */ PCI_DEV_FLAG_PCIE_BRIDGE_ALIAS = (__force pci_dev_flags_t) (1 << 5), + /* Do not use bus resets for device */ + PCI_DEV_FLAGS_NO_BUS_RESET = (__force pci_dev_flags_t) (1 << 6), }; enum pci_irq_reroute_variant { From c3e59ee4e76686b0c84ca8faa1011d10cd4ca1b8 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Thu, 15 Jan 2015 18:17:12 -0600 Subject: [PATCH 03/10] PCI: Mark Atheros AR93xx to avoid bus reset Reports against the TL-WDN4800 card indicate that PCI bus reset of this Atheros device cause system lock-ups and resets. I've also been able to confirm this behavior on multiple systems. The device never returns from reset and attempts to access config space of the device after reset result in hangs. Blacklist bus reset for the device to avoid this issue. [bhelgaas: This regression appeared in v3.14. Andreas bisected it to 425c1b223dac ("PCI: Add Virtual Channel to save/restore support"), but we don't understand the mechanism by which that commit affects the reset path.] [bhelgaas: changelog, references] Link: http://lkml.kernel.org/r/20140923210318.498dacbd@dualc.maya.org Reported-by: Andreas Hartmann Tested-by: Andreas Hartmann Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas CC: stable@vger.kernel.org # v3.14+ --- drivers/pci/quirks.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index ed6f89b6efe5..e52356aa09b8 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3028,6 +3028,20 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_REALTEK, 0x8169, DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MELLANOX, PCI_ANY_ID, quirk_broken_intx_masking); +static void quirk_no_bus_reset(struct pci_dev *dev) +{ + dev->dev_flags |= PCI_DEV_FLAGS_NO_BUS_RESET; +} + +/* + * Atheros AR93xx chips do not behave after a bus reset. The device will + * throw a Link Down error on AER-capable systems and regardless of AER, + * config space of the device is never accessible again and typically + * causes the system to hang or reset when access is attempted. + * http://www.spinics.net/lists/linux-pci/msg34797.html + */ +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0030, quirk_no_bus_reset); + #ifdef CONFIG_ACPI /* * Apple: Shutdown Cactus Ridge Thunderbolt controller. From 51e537387990dc1f00752103f314fd135cb94bc6 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Fri, 21 Nov 2014 11:24:08 -0700 Subject: [PATCH 04/10] PCI: Add flag for devices that don't reset on D3hot->D0 transition Per the PCI Power Management spec r1.2, sec 3.2.4, a device that advertises No_Soft_Reset == 0 in the PMCSR register (reported by lspci as "NoSoftRst-") should perform an internal reset when transitioning from D3hot to D0 via software control. Configuration context is lost and the device requires a full reinitialization sequence. Unfortunately the definition of "internal reset", beyond the application of the configuration context, is largely left to the interpretation of the specific device. Some devices don't seem to perform an "internal reset" even if they report No_Soft_Reset == 0. We still need to honor the PCI specification and restore PCI config context in the event that we do a PM reset, so we don't cache and modify the PCI_PM_CTRL_NO_SOFT_RESET bit for the device, but for interfaces where the intention is to reset the device, like pci_reset_function(), we need a mechanism to flag that PM reset (a D3hot->D0 transition) doesn't perform any significant "internal reset" of the device. Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 2 +- include/linux/pci.h | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e9d4fd861ba1..422bc0179e90 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3197,7 +3197,7 @@ static int pci_pm_reset(struct pci_dev *dev, int probe) { u16 csr; - if (!dev->pm_cap) + if (!dev->pm_cap || dev->dev_flags & PCI_DEV_FLAGS_NO_PM_RESET) return -ENOTTY; pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr); diff --git a/include/linux/pci.h b/include/linux/pci.h index 44627f1df4ca..7bed32b3fd54 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -177,6 +177,8 @@ enum pci_dev_flags { PCI_DEV_FLAG_PCIE_BRIDGE_ALIAS = (__force pci_dev_flags_t) (1 << 5), /* Do not use bus resets for device */ PCI_DEV_FLAGS_NO_BUS_RESET = (__force pci_dev_flags_t) (1 << 6), + /* Do not use PM reset even if device advertises NoSoftRst- */ + PCI_DEV_FLAGS_NO_PM_RESET = (__force pci_dev_flags_t) (1 << 7), }; enum pci_irq_reroute_variant { From d84f31744643e2c439466d513ebc1bc81c4d9186 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Fri, 21 Nov 2014 11:24:14 -0700 Subject: [PATCH 05/10] PCI: Mark AMD/ATI VGA devices that don't reset on D3hot->D0 transition Some AMD/ATI GPUs report NoSoftRst- to indicate that they perform a reset when software transitions them from D3hot to D0, but there is no apparent effect on the device: the monitor remains synced and the framebuffer contents are retained. Callers of pci_reset_function() don't necessarily have a way to validate whether a reset was effective, so we don't want to rely on NoSoftRst if it's known to be inaccurate. Returning an error in such cases appears to be the better option. For users like vfio-pci, this allows the driver to escalate to the bus reset interfaces. If a device lives on the root bus, there's really no further escalation path, so we exempt PM reset as potentially better than nothing. Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas Acked-by: Alex Deucher --- drivers/pci/quirks.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index e52356aa09b8..31e7972ca1b5 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3042,6 +3042,27 @@ static void quirk_no_bus_reset(struct pci_dev *dev) */ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0030, quirk_no_bus_reset); +static void quirk_no_pm_reset(struct pci_dev *dev) +{ + /* + * We can't do a bus reset on root bus devices, but an ineffective + * PM reset may be better than nothing. + */ + if (!pci_is_root_bus(dev->bus)) + dev->dev_flags |= PCI_DEV_FLAGS_NO_PM_RESET; +} + +/* + * Some AMD/ATI GPUS (HD8570 - Oland) report that a D3hot->D0 transition + * causes a reset (i.e., they advertise NoSoftRst-). This transition seems + * to have no effect on the device: it retains the framebuffer contents and + * monitor sync. Advertising this support makes other layers, like VFIO, + * assume pci_reset_function() is viable for this device. Mark it as + * unavailable to skip it when testing reset methods. + */ +DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_VENDOR_ID_ATI, PCI_ANY_ID, + PCI_CLASS_DISPLAY_VGA, 8, quirk_no_pm_reset); + #ifdef CONFIG_ACPI /* * Apple: Shutdown Cactus Ridge Thunderbolt controller. From 6a3763d1734bf133330dc8e246bf794b9e360e8a Mon Sep 17 00:00:00 2001 From: Vasundhara Volam Date: Tue, 13 Jan 2015 01:22:23 -0500 Subject: [PATCH 06/10] PCI: Add ACS quirk for Emulex NICs As Skyhawk and BE3-R (both multi-function devices) don't advertise the PCI-ACS capability, the vfio driver places all the functions of these devices in a single IOMMU group. Attaching (via PCI-passthru) two different Skyhawk/BE3-R partitions (nPAR, Flex, etc. PFs) using vfio, to different guests doesn't work as vfio only allows functions in *different* IOMMU groups to be assigned to different guests. As peer-to-peer access between PFs in Skyhawk/BE3-R is not possible, we can treat them as "fully isolated" even though the device doesn't advertise ACS. Add a PCI quirk for Skyhawk and BE3-R chips to fix this problem. Signed-off-by: Vasundhara Volam Signed-off-by: Sathya Perla Signed-off-by: Bjorn Helgaas Acked-by: Alex Williamson --- drivers/pci/quirks.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 31e7972ca1b5..3fb378aa7c53 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3748,6 +3748,8 @@ static const struct pci_dev_acs_enabled { { PCI_VENDOR_ID_INTEL, 0x1551, pci_quirk_mf_endpoint_acs }, { PCI_VENDOR_ID_INTEL, 0x1558, pci_quirk_mf_endpoint_acs }, { PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_quirk_intel_pch_acs }, + { 0x19a2, 0x710, pci_quirk_mf_endpoint_acs }, /* Emulex BE3-R */ + { 0x10df, 0x720, pci_quirk_mf_endpoint_acs }, /* Emulex Skyhawk-R */ { 0 } }; From a93b506e265a83a0f8c56ff003434e2d263961ce Mon Sep 17 00:00:00 2001 From: Bjorn Helgaas Date: Wed, 21 Jan 2015 10:28:07 -0600 Subject: [PATCH 07/10] PCI: pciehp: Handle surprise add even if surprise removal isn't supported The PCIe spec (r3.0, sec 7.8.9) says Hot-Plug Surprise indicates support for surprise *removal*, but pciehp checked this to determine if it should handle presence detect interrupts for device *addition*. Allow surprise device addition even if the slot doesn't advertise support for surprise removal. Keith has a platform with slots for front-loading SFF devices. The slots do not have attention buttons and do not support surprise removal, but they do have presence detect. In that case, we still want to use presence detect for device addition. Keith's original patch handled surprise insertions only if Hot-Plug Capable is set. I think that test is superfluous because pciehp only claims slots that advertise Hot-Plug Capable (see get_port_device_capability()). Link: http://lkml.kernel.org/r/1419275223-14602-1-git-send-email-keith.busch@intel.com Based-on-patch-by: Keith Busch Signed-off-by: Bjorn Helgaas Acked-by: Rajat Jain --- drivers/pci/hotplug/pciehp_ctrl.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp_ctrl.c index ff32e85e1de6..f052e951b23e 100644 --- a/drivers/pci/hotplug/pciehp_ctrl.c +++ b/drivers/pci/hotplug/pciehp_ctrl.c @@ -532,8 +532,6 @@ static void interrupt_event_handler(struct work_struct *work) pciehp_green_led_off(p_slot); break; case INT_PRESENCE_ON: - if (!HP_SUPR_RM(ctrl)) - break; ctrl_dbg(ctrl, "Surprise Insertion\n"); handle_surprise_event(p_slot); break; From d3d2ab43ddae5f958461ac0a9a2b484a68194df5 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Tue, 13 Jan 2015 11:26:50 -0700 Subject: [PATCH 08/10] PCI: Add DMA alias quirk for Adaptec 3405 The Adaptec 3405 is actually an Intel 80333 I/O processor where the exposed device at 0e.0 is actually the address translation unit of the I/O processor and a hidden, private device at 01.0 masters the DMA for the device. Create a fixed alias between the exposed and hidden devfn so we can enable the IOMMU. Scenarios like this are potentially likely for any device incorporating this I/O processor, so this little bit of abstraction with the fixed alias table should make future additions trivial. Without this fix, booting a system with the Intel IOMMU enabled and an Adaptec 3405 at 02:0e.0 results in a flood of errors like this: dmar: DRHD: handling fault status reg 3 dmar: DMAR:[DMA Write] Request device [02:01.0] fault addr ffbff000 DMAR:[fault reason 02] Present bit in context entry is clear [bhelgaas: changelog, comment] Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas CC: Adaptec OEM Raid Solutions --- drivers/pci/quirks.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 3fb378aa7c53..45bd8704c99d 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3562,6 +3562,44 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_JMICRON, PCI_DEVICE_ID_JMICRON_JMB388_ESD, quirk_dma_func1_alias); +/* + * Some devices DMA with the wrong devfn, not just the wrong function. + * quirk_fixed_dma_alias() uses this table to create fixed aliases, where + * the alias is "fixed" and independent of the device devfn. + * + * For example, the Adaptec 3405 is a PCIe card with an Intel 80333 I/O + * processor. To software, this appears as a PCIe-to-PCI/X bridge with a + * single device on the secondary bus. In reality, the single exposed + * device at 0e.0 is the Address Translation Unit (ATU) of the controller + * that provides a bridge to the internal bus of the I/O processor. The + * controller supports private devices, which can be hidden from PCI config + * space. In the case of the Adaptec 3405, a private device at 01.0 + * appears to be the DMA engine, which therefore needs to become a DMA + * alias for the device. + */ +static const struct pci_device_id fixed_dma_alias_tbl[] = { + { PCI_DEVICE_SUB(PCI_VENDOR_ID_ADAPTEC2, 0x0285, + PCI_VENDOR_ID_ADAPTEC2, 0x02bb), /* Adaptec 3405 */ + .driver_data = PCI_DEVFN(1, 0) }, + { 0 } +}; + +static void quirk_fixed_dma_alias(struct pci_dev *dev) +{ + const struct pci_device_id *id; + + id = pci_match_id(fixed_dma_alias_tbl, dev); + if (id) { + dev->dma_alias_devfn = id->driver_data; + dev->dev_flags |= PCI_DEV_FLAGS_DMA_ALIAS_DEVFN; + dev_info(&dev->dev, "Enabling fixed DMA alias to %02x.%d\n", + PCI_SLOT(dev->dma_alias_devfn), + PCI_FUNC(dev->dma_alias_devfn)); + } +} + +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ADAPTEC2, 0x0285, quirk_fixed_dma_alias); + /* * A few PCIe-to-PCI bridges fail to expose a PCIe capability, resulting in * using the wrong DMA alias for the device. Some of these devices can be From 78e883585db49aa6d86b8817b770d7717699ab4e Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Thu, 22 Jan 2015 11:15:43 -0700 Subject: [PATCH 09/10] PCI: Add Wellsburg (X99) to Intel PCH root port ACS quirk Intel has confirmed that the Wellsburg chipset, while not reporting ACS, does provide the proper isolation through the RCBA/BSPR registers, so the same quirk works for this set of device IDs. Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas Acked-by: Don Dugger --- drivers/pci/quirks.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 45bd8704c99d..e248a119f15a 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3703,6 +3703,9 @@ static const u16 pci_quirk_intel_pch_acs_ids[] = { 0x9c98, 0x9c99, 0x9c9a, 0x9c9b, /* Patsburg (X79) PCH */ 0x1d10, 0x1d12, 0x1d14, 0x1d16, 0x1d18, 0x1d1a, 0x1d1c, 0x1d1e, + /* Wellsburg (X99) PCH */ + 0x8d10, 0x8d11, 0x8d12, 0x8d13, 0x8d14, 0x8d15, 0x8d16, 0x8d17, + 0x8d18, 0x8d19, 0x8d1a, 0x8d1b, 0x8d1c, 0x8d1d, 0x8d1e, }; static bool pci_quirk_intel_pch_acs_match(struct pci_dev *dev) From 16b036af31e1456cb69243a5a0c9ef801ecd1f17 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Michel=20D=C3=A4nzer?= Date: Mon, 19 Jan 2015 17:53:20 +0900 Subject: [PATCH 10/10] PCI: Fix infinite loop with ROM image of size 0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If the image size would ever read as 0, pci_get_rom_size() could keep processing the same image over and over again. Exit the loop if we ever read a length of zero. This fixes a soft lockup on boot when the radeon driver calls pci_get_rom_size() on an AMD Radeon R7 250X PCIe discrete graphics card. [bhelgaas: changelog, reference] Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1386973 Reported-by: Federico Signed-off-by: Michel Dänzer Signed-off-by: Bjorn Helgaas Reviewed-by: Alex Deucher CC: stable@vger.kernel.org --- drivers/pci/rom.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c index f955edb9bea7..eb0ad530dc43 100644 --- a/drivers/pci/rom.c +++ b/drivers/pci/rom.c @@ -71,6 +71,7 @@ size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom, size_t size) { void __iomem *image; int last_image; + unsigned length; image = rom; do { @@ -93,9 +94,9 @@ size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom, size_t size) if (readb(pds + 3) != 'R') break; last_image = readb(pds + 21) & 0x80; - /* this length is reliable */ - image += readw(pds + 16) * 512; - } while (!last_image); + length = readw(pds + 16); + image += length * 512; + } while (length && !last_image); /* never return a size larger than the PCI resource window */ /* there are known ROMs that get the size wrong */