On Thu, Feb 03, 2022 at 08:07:31PM +0100, Lukas Wunner wrote: > Hi Bjorn, > > the below patch is marked "Changes Requested" in patchwork: > > https://patchwork.kernel.org/project/linux-pci/patch/20211111054258.7309-1-zhangliguang@xxxxxxxxxxxxxxxxx/ > > I think that might be erroneous because the patch is correct, > I've provided a Reviewed-by and no change requests are recorded > in patchwork or the mailing list archive. > > If you've got a few minutes to spare, could you double-check the > state in patchwork and provide Liguang Zhang with the changes you'd > want (if any)? Thanks for reminding me about this. I don't remember why I marked it "changes requested" but I often do that if there's been significant discussion. In this case you also provided additional information (Fixes tag, bugzilla link, commit log elaboration) that should be included. Given that, I would typically wait for the author to repost it and incorporate the additional information. But I applied it to pci/hotplug with the commit log below. commit 92912b175178 ("PCI: pciehp: Clear cmd_busy bit in polling mode") Author: Liguang Zhang <zhangliguang@xxxxxxxxxxxxxxxxx> Date: Thu Nov 11 13:42:58 2021 +0800 PCI: pciehp: Clear cmd_busy bit in polling mode Writes to a Downstream Port's Slot Control register are PCIe hotplug "commands." If the Port supports Command Completed events, software must wait for a command to complete before writing to Slot Control again. pcie_do_write_cmd() sets ctrl->cmd_busy when it writes to Slot Control. If software notification is enabled, i.e., PCI_EXP_SLTCTL_HPIE and PCI_EXP_SLTCTL_CCIE are set, ctrl->cmd_busy is cleared by pciehp_isr(). But when software notification is disabled, as it is when pcie_init() powers off an empty slot, pcie_wait_cmd() uses pcie_poll_cmd() to poll for command completion, and it neglects to clear ctrl->cmd_busy, which leads to spurious timeouts: pcieport 0000:00:03.0: pciehp: Timeout on hotplug command 0x01c0 (issued 2264 msec ago) pcieport 0000:00:03.0: pciehp: Timeout on hotplug command 0x05c0 (issued 2288 msec ago) Clear ctrl->cmd_busy in pcie_poll_cmd() when it detects a Command Completed event (PCI_EXP_SLTSTA_CC). [bhelgaas: commit log] Fixes: a5dd4b4b0570 ("PCI: pciehp: Wait for hotplug command completion where necessary") Link: https://lore.kernel.org/r/20211111054258.7309-1-zhangliguang@xxxxxxxxxxxxxxxxx Link: https://bugzilla.kernel.org/show_bug.cgi?id=215143 Link: https://lore.kernel.org/r/20211126173309.GA12255@xxxxxxxxx Signed-off-by: Liguang Zhang <zhangliguang@xxxxxxxxxxxxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Reviewed-by: Lukas Wunner <lukas@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx # v4.19+
