From 6592e02ae4bd7b277230aa0c5821588a13b9d8e3 Mon Sep 17 00:00:00 2001 From: Kenji Kaneshige Date: Tue, 27 May 2008 19:05:26 +0900 Subject: [PATCH] pciehp: poll cmd completion if hotplug interrupt is disabled Fix improper long wait for command completion in pciehp probing. As described in PCI Express specification, software notification is not generated if the command that occurs as a result of a write to the Slot Control register that disables software notification of command completed events. Since pciehp driver doesn't take it into account, such command is issued in pciehp probing, and it causes improper long wait for command completion. This patch changes the pciehp driver to take such command into account. Signed-off-by: Kenji Kaneshige Signed-off-by: Kristen Carlson Accardi Signed-off-by: Jesse Barnes --- drivers/pci/hotplug/pciehp_hpc.c | 42 +++++++++++++++++++++++++++++--- 1 file changed, 38 insertions(+), 4 deletions(-) diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 70940fb3fffa..eb631af94738 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -247,14 +247,38 @@ static inline void pciehp_free_irq(struct controller *ctrl) free_irq(ctrl->pci_dev->irq, ctrl); } -static inline int pcie_wait_cmd(struct controller *ctrl) +static inline int pcie_poll_cmd(struct controller *ctrl) +{ + u16 slot_status; + int timeout = 1000; + + if (!pciehp_readw(ctrl, SLOTSTATUS, &slot_status)) + if (slot_status & CMD_COMPLETED) + goto completed; + for (timeout = 1000; timeout > 0; timeout -= 100) { + msleep(100); + if (!pciehp_readw(ctrl, SLOTSTATUS, &slot_status)) + if (slot_status & CMD_COMPLETED) + goto completed; + } + return 0; /* timeout */ + +completed: + pciehp_writew(ctrl, SLOTSTATUS, CMD_COMPLETED); + return timeout; +} + +static inline int pcie_wait_cmd(struct controller *ctrl, int poll) { int retval = 0; unsigned int msecs = pciehp_poll_mode ? 2500 : 1000; unsigned long timeout = msecs_to_jiffies(msecs); int rc; - rc = wait_event_interruptible_timeout(ctrl->queue, + if (poll) + rc = pcie_poll_cmd(ctrl); + else + rc = wait_event_interruptible_timeout(ctrl->queue, !ctrl->cmd_busy, timeout); if (!rc) dbg("Command not completed in 1000 msec\n"); @@ -331,8 +355,18 @@ static int pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask) /* * Wait for command completion. */ - if (!retval && !ctrl->no_cmd_complete) - retval = pcie_wait_cmd(ctrl); + if (!retval && !ctrl->no_cmd_complete) { + int poll = 0; + /* + * if hotplug interrupt is not enabled or command + * completed interrupt is not enabled, we need to poll + * command completed event. + */ + if (!(slot_ctrl & HP_INTR_ENABLE) || + !(slot_ctrl & CMD_CMPL_INTR_ENABLE)) + poll = 1; + retval = pcie_wait_cmd(ctrl, poll); + } out: mutex_unlock(&ctrl->ctrl_lock); return retval; -- 2.20.1