PCI: Lengthen reset delay for VideoPropulsion Torrent QN16e card
[ Upstream commit c9260693aa0c1e029ed23693cfd4d7814eee6624 ] Commit ac91e698 ("PCI: Unify delay handling for reset and resume") shortened an unconditional 1 sec delay after a Secondary Bus Reset to 100 msec for PCIe (per PCIe r6.1 sec 6.6.1). The 1 sec delay is only required for Conventional PCI. But it turns out that there are PCIe devices which require a longer delay than prescribed before first config space access after reset recovery or resume from D3cold: Chad reports that a "VideoPropulsion Torrent QN16e" MPEG QAM Modulator "raises a PCI system error (PERR), as reported by the IPMI event log, and the hardware itself would suffer a catastrophic event, cycling the server" unless the longer delay is observed. The card is specified to conform to PCIe r1.0 and indeed only supports Gen1 speed (2.5 GT/s) according to lspci. PCIe r1.0 sec 7.6 prescribes the same 100 msec delay as PCIe r6.1 sec 6.6.1: To allow components to perform internal initialization, system software must wait for at least 100 ms from the end of a reset (cold/warm/hot) before it is permitted to issue Configuration Requests The behavior of the Torrent QN16e card thus appears to be a quirk. Treat it as such and lengthen the reset delay for this specific device. Fixes: ac91e698 ("PCI: Unify delay handling for reset and resume") Link: https://lore.kernel.org/r/47727e792c7f0282dc144e3ec8ce8eb6e713394e.1695304512.git.lukas@wunner.de Reported-by:Chad Schroeder <CSchroeder@sonifi.com> Closes: https://lore.kernel.org/linux-pci/DM6PR16MB2844903E34CAB910082DF019B1FAA@DM6PR16MB2844.namprd16.prod.outlook.com/ Tested-by:
Chad Schroeder <CSchroeder@sonifi.com> Signed-off-by:
Lukas Wunner <lukas@wunner.de> Signed-off-by:
Bjorn Helgaas <bhelgaas@google.com> Cc: stable@vger.kernel.org # v5.4+ Signed-off-by:
Sasha Levin <sashal@kernel.org>
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