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Commit e4a082c7 authored by Sumant Patro's avatar Sumant Patro Committed by James Bottomley
Browse files

[SCSI] megaraid_sas: switch fw_outstanding to an atomic_t 



This patch( originally submitted by Christoph Hellwig) removes
instance_lock and changes fw_outstanding variable data type to
atomic_t.

Signed-off-by: default avatarSumant Patro <Sumant.Patro@lsil.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent f70e9c5f

Documentation/scsi/ChangeLog.megaraid_sas

+13 −0
Original line number Diff line number Diff line 


1 Release Date    : Wed Feb 03 14:31:44 PST 2006 - Sumant Patro <Sumant.Patro@lsil.com>

2 Current Version : 00.00.02.04

3 Older Version   : 00.00.02.04 



i.	Remove superflous instance_lock



	gets rid of the otherwise superflous instance_lock and avoids an unsave 

	unsynchronized access in the error handler.



		- Christoph Hellwig <hch@lst.de>





1 Release Date    : Wed Feb 03 14:31:44 PST 2006 - Sumant Patro <Sumant.Patro@lsil.com>

2 Current Version : 00.00.02.04

3 Older Version   : 00.00.02.04

drivers/scsi/megaraid/megaraid_sas.c

+10 −16
Original line number Diff line number Diff line
@@ -741,7 +741,6 @@ static int 
megasas_queue_command(struct scsi_cmnd *scmd, void (*done) (struct scsi_cmnd *))

{

	u32 frame_count;

	unsigned long flags;

	struct megasas_cmd *cmd;

	struct megasas_instance *instance;
@@ -776,9 +775,7 @@ megasas_queue_command(struct scsi_cmnd *scmd, void (*done) (struct scsi_cmnd *)) 
	/*

	 * Issue the command to the FW

	 */

	spin_lock_irqsave(&instance->instance_lock, flags);

	instance->fw_outstanding++;

	spin_unlock_irqrestore(&instance->instance_lock, flags);

	atomic_inc(&instance->fw_outstanding);



	instance->instancet->fire_cmd(cmd->frame_phys_addr ,cmd->frame_count-1,instance->reg_set);
@@ -826,19 +823,20 @@ static int megasas_wait_for_outstanding(struct megasas_instance *instance) 


	for (i = 0; i < wait_time; i++) {



		if (!instance->fw_outstanding)

		int outstanding = atomic_read(&instance->fw_outstanding);



		if (!outstanding)

			break;



		if (!(i % MEGASAS_RESET_NOTICE_INTERVAL)) {

			printk(KERN_NOTICE "megasas: [%2d]waiting for %d "

			       "commands to complete\n", i,

			       instance->fw_outstanding);

			       "commands to complete\n",i,outstanding);

		}



		msleep(1000);

	}



	if (instance->fw_outstanding) {

	if (atomic_read(&instance->fw_outstanding)) {

		instance->hw_crit_error = 1;

		return FAILED;

	}
@@ -1050,7 +1048,6 @@ megasas_complete_cmd(struct megasas_instance *instance, struct megasas_cmd *cmd, 
{

	int exception = 0;

	struct megasas_header *hdr = &cmd->frame->hdr;

	unsigned long flags;



	if (cmd->scmd) {

		cmd->scmd->SCp.ptr = (char *)0;
@@ -1082,9 +1079,7 @@ megasas_complete_cmd(struct megasas_instance *instance, struct megasas_cmd *cmd, 


		if (exception) {



			spin_lock_irqsave(&instance->instance_lock, flags);

			instance->fw_outstanding--;

			spin_unlock_irqrestore(&instance->instance_lock, flags);

			atomic_dec(&instance->fw_outstanding);



			megasas_unmap_sgbuf(instance, cmd);

			cmd->scmd->scsi_done(cmd->scmd);
@@ -1132,9 +1127,7 @@ megasas_complete_cmd(struct megasas_instance *instance, struct megasas_cmd *cmd, 
			break;

		}



		spin_lock_irqsave(&instance->instance_lock, flags);

		instance->fw_outstanding--;

		spin_unlock_irqrestore(&instance->instance_lock, flags);

		atomic_dec(&instance->fw_outstanding);



		megasas_unmap_sgbuf(instance, cmd);

		cmd->scmd->scsi_done(cmd->scmd);
@@ -2171,11 +2164,12 @@ megasas_probe_one(struct pci_dev *pdev, const struct pci_device_id *id) 
	 */

	INIT_LIST_HEAD(&instance->cmd_pool);



	atomic_set(&instance->fw_outstanding,0);



	init_waitqueue_head(&instance->int_cmd_wait_q);

	init_waitqueue_head(&instance->abort_cmd_wait_q);



	spin_lock_init(&instance->cmd_pool_lock);

	spin_lock_init(&instance->instance_lock);



	sema_init(&instance->aen_mutex, 1);

	sema_init(&instance->ioctl_sem, MEGASAS_INT_CMDS);

drivers/scsi/megaraid/megaraid_sas.h

+1 −2
Original line number Diff line number Diff line
@@ -1077,9 +1077,8 @@ struct megasas_instance { 
	struct pci_dev *pdev;

	u32 unique_id;



	u32 fw_outstanding;

	atomic_t fw_outstanding;

	u32 hw_crit_error;

	spinlock_t instance_lock;



	struct megasas_instance_template *instancet;

};