From kristen.c.accardi@intel.com Thu Dec 21 17:01:38 2006 From: Kenji Kaneshige To: akpm@osdl.org Cc: greg@kroah.com, Kenji Kaneshige Subject: [PATCH 9/10] pciehp: fix wait command completion Date: Thu, 21 Dec 2006 17:01:10 -0800 Message-Id: <11667492762909-git-send-email-kristen.c.accardi@intel.com> From: Kenji Kaneshige This patch fixes this problem that pciehp driver will sleep unnecessarily long when waiting for command completion. With this patch, modprobe pciehp driver becomes very faster as follows for instance. o Without this patch # time /sbin/modprobe pciehp real 0m4.976s user 0m0.000s sys 0m0.004s o With this patch # time /sbin/modprobe pciehp real 0m0.640s user 0m0.000s sys 0m0.004s Signed-off-by: Kenji Kaneshige Signed-off-by: Kristen Carlson Accardi Signed-off-by: Greg Kroah-Hartman --- drivers/pci/hotplug/pciehp.h | 1 + drivers/pci/hotplug/pciehp_hpc.c | 27 +++++++++++++++------------ 2 files changed, 16 insertions(+), 12 deletions(-) --- gregkh-2.6.orig/drivers/pci/hotplug/pciehp.h +++ gregkh-2.6/drivers/pci/hotplug/pciehp.h @@ -100,6 +100,7 @@ struct controller { u16 vendor_id; u8 cap_base; struct timer_list poll_timer; + volatile int cmd_busy; }; #define INT_BUTTON_IGNORE 0 --- gregkh-2.6.orig/drivers/pci/hotplug/pciehp_hpc.c +++ gregkh-2.6/drivers/pci/hotplug/pciehp_hpc.c @@ -251,20 +251,21 @@ static void start_int_poll_timer(struct static inline int pcie_wait_cmd(struct controller *ctrl) { - DECLARE_WAITQUEUE(wait, current); - - add_wait_queue(&ctrl->queue, &wait); - if (!pciehp_poll_mode) - /* Sleep for up to 1 second */ - msleep_interruptible(1000); - else - msleep_interruptible(2500); + int retval = 0; + unsigned int msecs = pciehp_poll_mode ? 2500 : 1000; + unsigned long timeout = msecs_to_jiffies(msecs); + int rc; - remove_wait_queue(&ctrl->queue, &wait); - if (signal_pending(current)) - return -EINTR; + rc = wait_event_interruptible_timeout(ctrl->queue, + !ctrl->cmd_busy, timeout); + if (!rc) + dbg("Command not completed in 1000 msec\n"); + else if (rc < 0) { + retval = -EINTR; + info("Command was interrupted by a signal\n"); + } - return 0; + return retval; } static int pcie_write_cmd(struct slot *slot, u16 cmd) @@ -291,6 +292,7 @@ static int pcie_write_cmd(struct slot *s __FUNCTION__); } + ctrl->cmd_busy = 1; retval = pciehp_writew(ctrl, SLOTCTRL, (cmd | CMD_CMPL_INTR_ENABLE)); if (retval) { err("%s: Cannot write to SLOTCTRL register\n", __FUNCTION__); @@ -773,6 +775,7 @@ static irqreturn_t pcie_isr(int irq, voi /* * Command Complete Interrupt Pending */ + ctrl->cmd_busy = 0; wake_up_interruptible(&ctrl->queue); }