kernel.git/drivers/pci/pcie, branch linux-4.19.y

PCI/ASPM: Use RMW accessors for changing LNKCTL

2023-09-23T08:48:05Z

[ Upstream commit e09060b3b6b4661278ff8e1b7b81a37d5ea86eae ] Don't assume that the device is fully under the control of ASPM and use RMW capability accessors which do proper locking to avoid losing concurrent updates to the register values. If configuration fails in pcie_aspm_configure_common_clock(), the function attempts to restore the old PCI_EXP_LNKCTL_CCC settings. Store only the old PCI_EXP_LNKCTL_CCC bit for the relevant devices rather than the content of the whole LNKCTL registers. It aligns better with how pcie_lnkctl_clear_and_set() expects its parameter and makes the code more obvious to understand. Suggested-by: Lukas Wunner Fixes: 2a42d9dba784 ("PCIe: ASPM: Break out of endless loop waiting for PCI config bits to switch") Fixes: 7d715a6c1ae5 ("PCI: add PCI Express ASPM support") Link: https://lore.kernel.org/r/20230717120503.15276-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Acked-by: "Rafael J. Wysocki" Signed-off-by: Sasha Levin

PCI/ASPM: Avoid link retraining race

2023-08-11T09:45:29Z

[ Upstream commit e7e39756363ad5bd83ddeae1063193d0f13870fd ] PCIe r6.0.1, sec 7.5.3.7, recommends setting the link control parameters, then waiting for the Link Training bit to be clear before setting the Retrain Link bit. This avoids a race where the LTSSM may not use the updated parameters if it is already in the midst of link training because of other normal link activity. Wait for the Link Training bit to be clear before toggling the Retrain Link bit to ensure that the LTSSM uses the updated link control parameters. [bhelgaas: commit log, return 0 (success)/-ETIMEDOUT instead of bool for both pcie_wait_for_retrain() and the existing pcie_retrain_link()] Suggested-by: Lukas Wunner Fixes: 7d715a6c1ae5 ("PCI: add PCI Express ASPM support") Link: https://lore.kernel.org/r/20230502083923.34562-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin

PCI/ASPM: Factor out pcie_wait_for_retrain()

2023-08-11T09:45:29Z

[ Upstream commit 9c7f136433d26592cb4d9cd00b4e15c33d9797c6 ] Factor pcie_wait_for_retrain() out from pcie_retrain_link(). No functional change intended. [bhelgaas: split out from https: //lore.kernel.org/r/20230502083923.34562-1-ilpo.jarvinen@linux.intel.com] Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Stable-dep-of: e7e39756363a ("PCI/ASPM: Avoid link retraining race") Signed-off-by: Sasha Levin

PCI/ASPM: Return 0 or -ETIMEDOUT from pcie_retrain_link()

2023-08-11T09:45:28Z

[ Upstream commit f5297a01ee805d7fa569d288ed65fc0f9ac9b03d ] "pcie_retrain_link" is not a question with a true/false answer, so "bool" isn't quite the right return type. Return 0 for success or -ETIMEDOUT if the retrain failed. No functional change intended. [bhelgaas: based on Ilpo's patch below] Link: https://lore.kernel.org/r/20230502083923.34562-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Bjorn Helgaas Stable-dep-of: e7e39756363a ("PCI/ASPM: Avoid link retraining race") Signed-off-by: Sasha Levin

PCI: Rework pcie_retrain_link() wait loop

2023-08-11T09:45:28Z

[ Upstream commit 658eec837b11fbfab9082ebf8da24d94cefa47c0 ] Transform wait code to a "do {} while (time_before())" loop as recommended by reviewer. No functional change intended. Signed-off-by: Stefan Mätje Signed-off-by: Bjorn Helgaas Reviewed-by: Andy Shevchenko Stable-dep-of: e7e39756363a ("PCI/ASPM: Avoid link retraining race") Signed-off-by: Sasha Levin

PCI/ASPM: Add missing newline in sysfs 'policy'

2020-08-19T06:14:58Z

[ Upstream commit 3167e3d340c092fd47924bc4d23117a3074ef9a9 ] When I cat ASPM parameter 'policy' by sysfs, it displays as follows. Add a newline for easy reading. Other sysfs attributes already include a newline. [root@localhost ~]# cat /sys/module/pcie_aspm/parameters/policy [default] performance powersave powersupersave [root@localhost ~]# Fixes: 7d715a6c1ae5 ("PCI: add PCI Express ASPM support") Link: https://lore.kernel.org/r/1594972765-10404-1-git-send-email-wangxiongfeng2@huawei.com Signed-off-by: Xiongfeng Wang Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin

PCI/PTM: Inherit Switch Downstream Port PTM settings from Upstream Port

2020-06-25T13:32:58Z

[ Upstream commit 7b38fd9760f51cc83d80eed2cfbde8b5ead9e93a ] Except for Endpoints, we enable PTM at enumeration-time. Previously we did not account for the fact that Switch Downstream Ports are not permitted to have a PTM capability; their PTM behavior is controlled by the Upstream Port (PCIe r5.0, sec 7.9.16). Since Downstream Ports don't have a PTM capability, we did not mark them as "ptm_enabled", which meant that pci_enable_ptm() on an Endpoint failed because there was no PTM path to it. Mark Downstream Ports as "ptm_enabled" if their Upstream Port has PTM enabled. Fixes: eec097d43100 ("PCI: Add pci_enable_ptm() for drivers to enable PTM on endpoints") Reported-by: Aditya Paluri Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin

PCI/ASPM: Allow ASPM on links to PCIe-to-PCI/PCI-X Bridges

2020-06-25T13:32:55Z

[ Upstream commit 66ff14e59e8a30690755b08bc3042359703fb07a ] 7d715a6c1ae5 ("PCI: add PCI Express ASPM support") added the ability for Linux to enable ASPM, but for some undocumented reason, it didn't enable ASPM on links where the downstream component is a PCIe-to-PCI/PCI-X Bridge. Remove this exclusion so we can enable ASPM on these links. The Dell OptiPlex 7080 mentioned in the bugzilla has a TI XIO2001 PCIe-to-PCI Bridge. Enabling ASPM on the link leading to it allows the Intel SoC to enter deeper Package C-states, which is a significant power savings. [bhelgaas: commit log] Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207571 Link: https://lore.kernel.org/r/20200505173423.26968-1-kai.heng.feng@canonical.com Signed-off-by: Kai-Heng Feng Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg Signed-off-by: Sasha Levin

PCI/ASPM: Allow re-enabling Clock PM

2020-04-29T14:31:16Z

[ Upstream commit 35efea32b26f9aacc99bf07e0d2cdfba2028b099 ] Previously Clock PM could not be re-enabled after being disabled by pci_disable_link_state() because clkpm_capable was reset. Change this by adding a clkpm_disable field similar to aspm_disable. Link: https://lore.kernel.org/r/4e8a66db-7d53-4a66-c26c-f0037ffaa705@gmail.com Signed-off-by: Heiner Kallweit Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin

PCI/ASPM: Clear the correct bits when enabling L1 substates

2020-04-17T08:48:46Z

commit 58a3862a10a317a81097ab0c78aecebabb1704f5 upstream. In pcie_config_aspm_l1ss(), we cleared the wrong bits when enabling ASPM L1 Substates. Instead of the L1.x enable bits (PCI_L1SS_CTL1_L1SS_MASK, 0xf), we cleared the Link Activation Interrupt Enable bit (PCI_L1SS_CAP_L1_PM_SS, 0x10). Clear the L1.x enable bits before writing the new L1.x configuration. [bhelgaas: changelog] Fixes: aeda9adebab8 ("PCI/ASPM: Configure L1 substate settings") Link: https://lore.kernel.org/r/1584093227-1292-1-git-send-email-yangyicong@hisilicon.com Signed-off-by: Yicong Yang Signed-off-by: Bjorn Helgaas CC: stable@vger.kernel.org # v4.11+ Signed-off-by: Greg Kroah-Hartman