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Commit f41b5cec authored by Hannes Reinecke's avatar Hannes Reinecke Committed by James Bottomley
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[SCSI] aic79xx bus reset update 



As James B. correctly noted, ahd_reset_channel() in
ahd_linux_bus_reset() should be protected by ahd_lock().  However, the
main reason for not doing so was a deadlock with the interesting
polling mechanism to detect the end a bus reset.

This patch replaces the polling mechanism with a saner signalling via
flags; it also gives us the benefit of detecting any multiple calls to
ahd_reset_channel().

Signed-off-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent 4d7db04a

drivers/scsi/aic7xxx/aic79xx.h

+1 −1
Original line number Diff line number Diff line
@@ -372,7 +372,7 @@ typedef enum { 
	AHD_CURRENT_SENSING   = 0x40000,

	AHD_SCB_CONFIG_USED   = 0x80000,/* No SEEPROM but SCB had info. */

	AHD_HP_BOARD	      = 0x100000,

	AHD_RESET_POLL_ACTIVE = 0x200000,

	AHD_BUS_RESET_ACTIVE  = 0x200000,

	AHD_UPDATE_PEND_CMDS  = 0x400000,

	AHD_RUNNING_QOUTFIFO  = 0x800000,

	AHD_HAD_FIRST_SEL     = 0x1000000

drivers/scsi/aic7xxx/aic79xx_core.c

+53 −61
Original line number Diff line number Diff line
@@ -207,7 +207,6 @@ static void ahd_add_scb_to_free_list(struct ahd_softc *ahd, 
static u_int		ahd_rem_wscb(struct ahd_softc *ahd, u_int scbid,

				     u_int prev, u_int next, u_int tid);

static void		ahd_reset_current_bus(struct ahd_softc *ahd);

static ahd_callback_t	ahd_reset_poll;

static ahd_callback_t	ahd_stat_timer;

#ifdef AHD_DUMP_SEQ

static void		ahd_dumpseq(struct ahd_softc *ahd);
@@ -1534,6 +1533,18 @@ ahd_handle_scsiint(struct ahd_softc *ahd, u_int intstat) 
	lqistat1 = ahd_inb(ahd, LQISTAT1);

	lqostat0 = ahd_inb(ahd, LQOSTAT0);

	busfreetime = ahd_inb(ahd, SSTAT2) & BUSFREETIME;



	/*

	 * Ignore external resets after a bus reset.

	 */

	if (((status & SCSIRSTI) != 0) && (ahd->flags & AHD_BUS_RESET_ACTIVE))

		return;



	/*

	 * Clear bus reset flag

	 */

	ahd->flags &= ~AHD_BUS_RESET_ACTIVE;



	if ((status0 & (SELDI|SELDO)) != 0) {

		u_int simode0;
@@ -7847,6 +7858,17 @@ ahd_reset_channel(struct ahd_softc *ahd, char channel, int initiate_reset) 
	int	found;

	u_int	fifo;

	u_int	next_fifo;

	uint8_t scsiseq;



	/*

	 * Check if the last bus reset is cleared

	 */

	if (ahd->flags & AHD_BUS_RESET_ACTIVE) {

		printf("%s: bus reset still active\n",

		       ahd_name(ahd));

		return 0;

	}

	ahd->flags |= AHD_BUS_RESET_ACTIVE;



	ahd->pending_device = NULL;
@@ -7860,6 +7882,12 @@ ahd_reset_channel(struct ahd_softc *ahd, char channel, int initiate_reset) 
	/* Make sure the sequencer is in a safe location. */

	ahd_clear_critical_section(ahd);



	/*

	 * Run our command complete fifos to ensure that we perform

	 * completion processing on any commands that 'completed'

	 * before the reset occurred.

	 */

	ahd_run_qoutfifo(ahd);

#ifdef AHD_TARGET_MODE

	if ((ahd->flags & AHD_TARGETROLE) != 0) {

		ahd_run_tqinfifo(ahd, /*paused*/TRUE);
@@ -7924,30 +7952,14 @@ ahd_reset_channel(struct ahd_softc *ahd, char channel, int initiate_reset) 
	ahd_clear_fifo(ahd, 1);



	/*

	 * Revert to async/narrow transfers until we renegotiate.

	 * Reenable selections

	 */

	max_scsiid = (ahd->features & AHD_WIDE) ? 15 : 7;

	for (target = 0; target <= max_scsiid; target++) {



		if (ahd->enabled_targets[target] == NULL)

			continue;

		for (initiator = 0; initiator <= max_scsiid; initiator++) {

			struct ahd_devinfo devinfo;



			ahd_compile_devinfo(&devinfo, target, initiator,

					    CAM_LUN_WILDCARD,

					    'A', ROLE_UNKNOWN);

			ahd_set_width(ahd, &devinfo, MSG_EXT_WDTR_BUS_8_BIT,

				      AHD_TRANS_CUR, /*paused*/TRUE);

			ahd_set_syncrate(ahd, &devinfo, /*period*/0,

					 /*offset*/0, /*ppr_options*/0,

					 AHD_TRANS_CUR, /*paused*/TRUE);

		}

	}

	ahd_outb(ahd, SIMODE1, ahd_inb(ahd, SIMODE1) | ENSCSIRST);

	scsiseq = ahd_inb(ahd, SCSISEQ_TEMPLATE);

	ahd_outb(ahd, SCSISEQ1, scsiseq & (ENSELI|ENRSELI|ENAUTOATNP));



#ifdef AHD_TARGET_MODE

	max_scsiid = (ahd->features & AHD_WIDE) ? 15 : 7;



#ifdef AHD_TARGET_MODE

	/*

	 * Send an immediate notify ccb to all target more peripheral

	 * drivers affected by this action.
@@ -7975,51 +7987,31 @@ ahd_reset_channel(struct ahd_softc *ahd, char channel, int initiate_reset) 
	/* Notify the XPT that a bus reset occurred */

	ahd_send_async(ahd, devinfo.channel, CAM_TARGET_WILDCARD,

		       CAM_LUN_WILDCARD, AC_BUS_RESET, NULL);

	ahd_restart(ahd);



	/*

	 * Freeze the SIMQ until our poller can determine that

	 * the bus reset has really gone away.  We set the initial

	 * timer to 0 to have the check performed as soon as possible

	 * from the timer context.

	 * Revert to async/narrow transfers until we renegotiate.

	 */

	if ((ahd->flags & AHD_RESET_POLL_ACTIVE) == 0) {

		ahd->flags |= AHD_RESET_POLL_ACTIVE;

		ahd_freeze_simq(ahd);

		ahd_timer_reset(&ahd->reset_timer, 0, ahd_reset_poll, ahd);

	}

	return (found);

}



	for (target = 0; target <= max_scsiid; target++) {



#define AHD_RESET_POLL_US 1000

static void

ahd_reset_poll(void *arg)

{

	struct	ahd_softc *ahd = arg;

	u_int	scsiseq1;

	u_long	s;

		if (ahd->enabled_targets[target] == NULL)

			continue;

		for (initiator = 0; initiator <= max_scsiid; initiator++) {

			struct ahd_devinfo devinfo;



	ahd_lock(ahd, &s);

	ahd_pause(ahd);

	ahd_update_modes(ahd);

	ahd_set_modes(ahd, AHD_MODE_SCSI, AHD_MODE_SCSI);

	ahd_outb(ahd, CLRSINT1, CLRSCSIRSTI);

	if ((ahd_inb(ahd, SSTAT1) & SCSIRSTI) != 0) {

		ahd_timer_reset(&ahd->reset_timer, AHD_RESET_POLL_US,

				ahd_reset_poll, ahd);

		ahd_unpause(ahd);

		ahd_unlock(ahd, &s);

		return;

			ahd_compile_devinfo(&devinfo, target, initiator,

					    CAM_LUN_WILDCARD,

					    'A', ROLE_UNKNOWN);

			ahd_set_width(ahd, &devinfo, MSG_EXT_WDTR_BUS_8_BIT,

				      AHD_TRANS_CUR, /*paused*/TRUE);

			ahd_set_syncrate(ahd, &devinfo, /*period*/0,

					 /*offset*/0, /*ppr_options*/0,

					 AHD_TRANS_CUR, /*paused*/TRUE);

		}

	}



	/* Reset is now low.  Complete chip reinitialization. */

	ahd_outb(ahd, SIMODE1, ahd_inb(ahd, SIMODE1) | ENSCSIRST);

	scsiseq1 = ahd_inb(ahd, SCSISEQ_TEMPLATE);

	ahd_outb(ahd, SCSISEQ1, scsiseq1 & (ENSELI|ENRSELI|ENAUTOATNP));

	ahd_unpause(ahd);

	ahd->flags &= ~AHD_RESET_POLL_ACTIVE;

	ahd_unlock(ahd, &s);

	ahd_release_simq(ahd);

	ahd_restart(ahd);



	return (found);

}



/**************************** Statistics Processing ***************************/

drivers/scsi/aic7xxx/aic79xx_osm.c

+4 −0
Original line number Diff line number Diff line
@@ -782,6 +782,7 @@ ahd_linux_bus_reset(struct scsi_cmnd *cmd) 
{

	struct ahd_softc *ahd;

	int    found;

	unsigned long flags;



	ahd = *(struct ahd_softc **)cmd->device->host->hostdata;

#ifdef AHD_DEBUG
@@ -789,8 +790,11 @@ ahd_linux_bus_reset(struct scsi_cmnd *cmd) 
		printf("%s: Bus reset called for cmd %p\n",

		       ahd_name(ahd), cmd);

#endif

	ahd_lock(ahd, &flags);



	found = ahd_reset_channel(ahd, scmd_channel(cmd) + 'A',

				  /*initiate reset*/TRUE);

	ahd_unlock(ahd, &flags);



	if (bootverbose)

		printf("%s: SCSI bus reset delivered. "