[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: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This commit is contained in:
Hannes Reinecke 2006-04-03 08:19:34 +02:00 committed by James Bottomley
parent 4d7db04a7a
commit f41b5cec9b
3 changed files with 60 additions and 64 deletions

View File

@ -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

View File

@ -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
*/
ahd_outb(ahd, SIMODE1, ahd_inb(ahd, SIMODE1) | ENSCSIRST);
scsiseq = ahd_inb(ahd, SCSISEQ_TEMPLATE);
ahd_outb(ahd, SCSISEQ1, scsiseq & (ENSELI|ENRSELI|ENAUTOATNP));
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);
}
}
#ifdef AHD_TARGET_MODE
max_scsiid = (ahd->features & AHD_WIDE) ? 15 : 7;
/*
* Send an immediate notify ccb to all target more peripheral
* drivers affected by this action.
@ -7975,53 +7987,33 @@ 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);
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_restart(ahd);
return (found);
}
#define AHD_RESET_POLL_US 1000
static void
ahd_reset_poll(void *arg)
{
struct ahd_softc *ahd = arg;
u_int scsiseq1;
u_long s;
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;
}
/* 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);
}
/**************************** Statistics Processing ***************************/
static void
ahd_stat_timer(void *arg)

View File

@ -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. "