From 5808639bfa98d69f77a481d759570d85f164fea0 Mon Sep 17 00:00:00 2001 From: Kenji Kaneshige Date: Tue, 27 May 2008 19:04:30 +0900 Subject: pciehp: fix slow probing Fix the "pciehp probing slow" problem reported from Jan C. Nordholz in http://bugzilla.kernel.org/show_bug.cgi?id=10751. The command completed bit in Slot Status register applies only to commands issued to control the attention indicator, power indicator, power controller, or electromechanical interlock. However, writes to other parts of the Slot Control register would end up writing to the control fields. Hence, any write to Slot Control register is considered as a command. However, if the controller doesn't support any of attention indicator, power indicator, power controller and electromechanical interlock, command completed bit would not set in writing to Slot Control register. In this case, we should not wait for command completed bit set, otherwise all commands would be considered not completed in timeout seconds (1 sec.). The cause of the problem is pciehp driver didn't take this situation into account. This patch changes pciehp to take it into account. This patch also add the check for "No Command Completed Support" bit in Slot Capability register. If it is set, we should not wait for command completed bit set as well. This problem seems to be revealed by the commit c27fb883dffe11aa4cb35ecea1fa1832ba45d4da that fixed the bug that pciehp did not wait for command completed properly (pciehp just ignored the command completion event). Signed-off-by: Kenji Kaneshige Signed-off-by: Kristen Carlson Accardi Signed-off-by: Jesse Barnes --- drivers/pci/hotplug/pciehp_hpc.c | 40 +++++++++++++++++++++++++++++++++------- 1 file changed, 33 insertions(+), 7 deletions(-) (limited to 'drivers/pci/hotplug/pciehp_hpc.c') diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 425a0f609977..70940fb3fffa 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -286,12 +286,28 @@ static int pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask) goto out; } - if ((slot_status & CMD_COMPLETED) == CMD_COMPLETED ) { - /* After 1 sec and CMD_COMPLETED still not set, just - proceed forward to issue the next command according - to spec. Just print out the error message */ - dbg("%s: CMD_COMPLETED not clear after 1 sec.\n", - __func__); + if (slot_status & CMD_COMPLETED) { + if (!ctrl->no_cmd_complete) { + /* + * After 1 sec and CMD_COMPLETED still not set, just + * proceed forward to issue the next command according + * to spec. Just print out the error message. + */ + dbg("%s: CMD_COMPLETED not clear after 1 sec.\n", + __func__); + } else if (!NO_CMD_CMPL(ctrl)) { + /* + * This controller semms to notify of command completed + * event even though it supports none of power + * controller, attention led, power led and EMI. + */ + dbg("%s: Unexpected CMD_COMPLETED. Need to wait for " + "command completed event.\n", __func__); + ctrl->no_cmd_complete = 0; + } else { + dbg("%s: Unexpected CMD_COMPLETED. Maybe the " + "controller is broken.\n", __func__); + } } retval = pciehp_readw(ctrl, SLOTCTRL, &slot_ctrl); @@ -315,7 +331,7 @@ static int pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask) /* * Wait for command completion. */ - if (!retval) + if (!retval && !ctrl->no_cmd_complete) retval = pcie_wait_cmd(ctrl); out: mutex_unlock(&ctrl->ctrl_lock); @@ -1130,6 +1146,7 @@ static inline void dbg_ctrl(struct controller *ctrl) dbg(" Power Indicator : %3s\n", PWR_LED(ctrl) ? "yes" : "no"); dbg(" Hot-Plug Surprise : %3s\n", HP_SUPR_RM(ctrl) ? "yes" : "no"); dbg(" EMI Present : %3s\n", EMI(ctrl) ? "yes" : "no"); + dbg(" Comamnd Completed : %3s\n", NO_CMD_CMPL(ctrl)? "no" : "yes"); pciehp_readw(ctrl, SLOTSTATUS, ®16); dbg("Slot Status : 0x%04x\n", reg16); pciehp_readw(ctrl, SLOTSTATUS, ®16); @@ -1161,6 +1178,15 @@ int pcie_init(struct controller *ctrl, struct pcie_device *dev) mutex_init(&ctrl->ctrl_lock); init_waitqueue_head(&ctrl->queue); dbg_ctrl(ctrl); + /* + * Controller doesn't notify of command completion if the "No + * Command Completed Support" bit is set in Slot Capability + * register or the controller supports none of power + * controller, attention led, power led and EMI. + */ + if (NO_CMD_CMPL(ctrl) || + !(POWER_CTRL(ctrl) | ATTN_LED(ctrl) | PWR_LED(ctrl) | EMI(ctrl))) + ctrl->no_cmd_complete = 1; info("HPC vendor_id %x device_id %x ss_vid %x ss_did %x\n", pdev->vendor, pdev->device, -- cgit v1.2.3