Commit 2396a265 authored by Dan Williams's avatar Dan Williams
Browse files

isci: fix interrupt disable 



There is a (dubious?) lost irq workaround in sci_controller_isr() that
effectively nullifies attempts to disable interrupts.  Until the
workaround can be re-evaluated add some infrastructure to prevent the
interrupt handler from inadvertantly re-enabling interrupts.

The failure mode was interrupts continuing to run after the driver had
been removed and its iomappings torn down.

Reported-by: default avatarJacek Danecki <jacek.danecki@intel.com>
Tested-by: default avatarJacek Danecki <jacek.danecki@intel.com>
[richard: clear remaining interrupts at the end of reset]
Acked-by: default avatarRichard Boyd <richard.g.boyd@intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 50a92d93

drivers/scsi/isci/host.c

+26 −13
Original line number Diff line number Diff line
@@ -192,22 +192,27 @@ static bool sci_controller_completion_queue_has_entries(struct isci_host *ihost) 


static bool sci_controller_isr(struct isci_host *ihost)

{

	if (sci_controller_completion_queue_has_entries(ihost)) {

	if (sci_controller_completion_queue_has_entries(ihost))

		return true;

	} else {

		/*

		 * we have a spurious interrupt it could be that we have already

		 * emptied the completion queue from a previous interrupt */



	/* we have a spurious interrupt it could be that we have already

	 * emptied the completion queue from a previous interrupt

	 * FIXME: really!?

	 */

	writel(SMU_ISR_COMPLETION, &ihost->smu_registers->interrupt_status);



		/*

		 * There is a race in the hardware that could cause us not to be notified

		 * of an interrupt completion if we do not take this step.  We will mask

		 * then unmask the interrupts so if there is another interrupt pending

		 * the clearing of the interrupt source we get the next interrupt message. */

	/* There is a race in the hardware that could cause us not to be

	 * notified of an interrupt completion if we do not take this

	 * step.  We will mask then unmask the interrupts so if there is

	 * another interrupt pending the clearing of the interrupt

	 * source we get the next interrupt message.

	 */

	spin_lock(&ihost->scic_lock);

	if (test_bit(IHOST_IRQ_ENABLED, &ihost->flags)) {

		writel(0xFF000000, &ihost->smu_registers->interrupt_mask);

		writel(0, &ihost->smu_registers->interrupt_mask);

	}

	spin_unlock(&ihost->scic_lock);



	return false;

}
@@ -698,14 +703,15 @@ static u32 sci_controller_get_suggested_start_timeout(struct isci_host *ihost) 


static void sci_controller_enable_interrupts(struct isci_host *ihost)

{

	BUG_ON(ihost->smu_registers == NULL);

	set_bit(IHOST_IRQ_ENABLED, &ihost->flags);

	writel(0, &ihost->smu_registers->interrupt_mask);

}



void sci_controller_disable_interrupts(struct isci_host *ihost)

{

	BUG_ON(ihost->smu_registers == NULL);

	clear_bit(IHOST_IRQ_ENABLED, &ihost->flags);

	writel(0xffffffff, &ihost->smu_registers->interrupt_mask);

	readl(&ihost->smu_registers->interrupt_mask); /* flush */

}



static void sci_controller_enable_port_task_scheduler(struct isci_host *ihost)
@@ -1318,7 +1324,9 @@ void isci_host_deinit(struct isci_host *ihost) 
	 */

	writel(0, &ihost->scu_registers->peg0.sgpio.interface_control);



	spin_lock_irq(&ihost->scic_lock);

	sci_controller_reset(ihost);

	spin_unlock_irq(&ihost->scic_lock);



	/* Cancel any/all outstanding port timers */

	for (i = 0; i < ihost->logical_port_entries; i++) {
@@ -1605,6 +1613,9 @@ static void sci_controller_reset_hardware(struct isci_host *ihost) 


	/* The write to the UFQGP clears the UFQPR */

	writel(0, &ihost->scu_registers->sdma.unsolicited_frame_get_pointer);



	/* clear all interrupts */

	writel(~SMU_INTERRUPT_STATUS_RESERVED_MASK, &ihost->smu_registers->interrupt_status);

}



static void sci_controller_resetting_state_enter(struct sci_base_state_machine *sm)
@@ -2391,7 +2402,9 @@ int isci_host_init(struct isci_host *ihost) 
	int i, err;

	enum sci_status status;



	spin_lock_irq(&ihost->scic_lock);

	status = sci_controller_construct(ihost, scu_base(ihost), smu_base(ihost));

	spin_unlock_irq(&ihost->scic_lock);

	if (status != SCI_SUCCESS) {

		dev_err(&ihost->pdev->dev,

			"%s: sci_controller_construct failed - status = %x\n",

drivers/scsi/isci/host.h

+1 −0
Original line number Diff line number Diff line
@@ -200,6 +200,7 @@ struct isci_host { 
	struct pci_dev *pdev;

	#define IHOST_START_PENDING 0

	#define IHOST_STOP_PENDING 1

	#define IHOST_IRQ_ENABLED 2

	unsigned long flags;

	wait_queue_head_t eventq;

	struct Scsi_Host *shost;

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