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linux-elphel
Commit d6018112 authored by Mikhail Karpenko's avatar Mikhail Karpenko
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Change cmd timer processing to fix a race condition

parent 3590b827
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Showing with 56 additions and 65 deletions
src/drivers/ata/ahci_elphel.c
View file @ d6018112
......@@ -144,7 +144,8 @@ static void remove_timer(struct elphel_ahci_priv *dpriv)
if (timer_pending(&dpriv->cmd_timer)) {
ret = del_timer_sync(&dpriv->cmd_timer);
if (ret < 0)
dev_err(dpriv->dev, "can not remove timer\n");
dev_err(dpriv->dev, "can not remove command guard timer\n");
reset_flag(dpriv, IRQ_PROCESSED);
}
}
......@@ -176,11 +177,22 @@ static void reset_all_commands(struct elphel_ahci_priv *dpriv)
/** Command execution timer has expired, set flag indicating that recording should be restarted */
static void process_timeout(unsigned long data)
{
int report = 0;
unsigned long irq_flags;
struct elphel_ahci_priv *dpriv = (struct elphel_ahci_priv *)data;
dev_err(dpriv->dev, "AHCI error: command execution timeout, LBA start = 0x%llx\n", dpriv->lba_ptr.lba_write);
set_dscope_tstamp(dpriv, TSTMP_CMD_SYS);
set_flag(dpriv, START_EH);
/* we are racing with interrupt here, IRQ handler sets IRQ_PROCESSED flag to prevent timer from
* triggering error handler before this timer is removed
*/
spin_lock_irqsave(&dpriv->flags_lock, irq_flags);
if (!(dpriv->flags & IRQ_PROCESSED)) {
dpriv->flags |= START_EH;
report = 1;
}
spin_unlock_irqrestore(&dpriv->flags_lock, irq_flags);
if (report) {
set_dscope_tstamp(dpriv, TSTMP_CMD_SYS);
}
}
/** Calculate the difference between two time stamps and return it in microseconds */
......@@ -232,26 +244,19 @@ static irqreturn_t elphel_irq_handler(int irq, void * dev_instance)
host_irq_stat = readl(hpriv->mmio + HOST_IRQ_STAT);
if (!host_irq_stat) {
dev_err(dpriv->dev, "Spurious IRQ received, host_irq_stat = 0x%x\n", host_irq_stat);
// debug actions, check it one more time before exit
host_irq_stat = readl(hpriv->mmio + HOST_IRQ_STAT);
if (!host_irq_stat) {
return IRQ_NONE;
} else {
dev_err(dpriv->dev, "Spurious interrupt not confirmed, host_irq_stat = 0x%x, proceed to IRQ processing\n", host_irq_stat);
}
return IRQ_NONE;
}
// dpriv->flags &= ~IRQ_SIMPLE;
reset_flag(dpriv, IRQ_SIMPLE);
irq_stat = readl(port_mmio + PORT_IRQ_STAT);
serror = readl(port_mmio + PORT_SCR_ERR);
/* debug feature, save current state for analysis */
dpriv->datascope.reg_stat[REG_HOST_IS] = host_irq_stat;
dpriv->datascope.reg_stat[REG_PxIS] = irq_stat;
dpriv->datascope.reg_stat[REG_PxSERR] = serror;
dpriv->datascope.reg_stat[REG_PxIE] = readl(port_mmio + PORT_IRQ_MASK);
dpriv->datascope.reg_stat[IRQ_COUNTER] = dpriv->datascope.reg_stat[IRQ_COUNTER] + 1;
// dev_dbg(host->dev, "irq_stat = 0x%x, host irq_stat = 0x%x, SErr = 0x%x\n", irq_stat, host_irq_stat, serror);
if (unlikely(irq_stat & PORT_IRQ_ERROR)) {
dpriv->eh.irq_stat = irq_stat;
......@@ -264,18 +269,21 @@ static irqreturn_t elphel_irq_handler(int irq, void * dev_instance)
handled = IRQ_HANDLED;
set_dscope_tstamp(dpriv, TSTMP_IRQ_MARK_1);
/* check if this command timed out and charged error handler, do not schedule tasklet in this case as
/*
* check if this command timed out and charged error handler, do not schedule tasklet in this case as
* the processing will restart from error handler
*/
spin_lock_irqsave(&dpriv->flags_lock, irq_flags);
if (dpriv->flags & (START_EH | WAIT_EH)) {
// tell to EH that the command will be processed in normal way
set_dscope_tstamp(dpriv, TSTMP_IRQ_MARK_1);
set_flag(dpriv, DELAYED_IRQ_RCVD);
dpriv->flags |= DELAYED_IRQ_RCVD;
wake_up_interruptible(&dpriv->eh.wait);
} else {
dpriv->flags |= IRQ_PROCESSED;
tasklet_schedule(&dpriv->bh);
}
spin_unlock_irqrestore(&dpriv->flags_lock, irq_flags);
} else {
set_dscope_tstamp(dpriv, TSTMP_IRQ_SYS);
......@@ -294,12 +302,12 @@ static irqreturn_t elphel_irq_handler(int irq, void * dev_instance)
return handled;
}
/** Command queue processing tasklet */
void process_queue(unsigned long data)
{
int i;
size_t total_sz = 0;
unsigned long irq_flags;
unsigned long time_usec;
sec_usec_t end_time = {0};
struct elphel_ahci_priv *dpriv = (struct elphel_ahci_priv *)data;
......@@ -313,9 +321,9 @@ void process_queue(unsigned long data)
add_sample(total_sz / time_usec, &dpriv->stat);
}
// check if we can proceed - this was debug feature to fully stop cmd processing
if (dpriv->flags & (START_EH | WAIT_EH))
return;
// // check if we can proceed - this was debug feature to fully stop cmd processing
// if (dpriv->flags & (START_EH | WAIT_EH))
// return;
if (process_cmd(dpriv) == 0) {
finish_cmd(dpriv);
......@@ -327,9 +335,6 @@ void process_queue(unsigned long data)
finish_rec(dpriv);
} else {
/* all commands have been processed */
// spin_lock_irqsave(&dpriv->flags_lock, irq_flags);
// dpriv->flags &= ~DISK_BUSY;
// spin_unlock_irqrestore(&dpriv->flags_lock, irq_flags);
reset_flag(dpriv, DISK_BUSY);
}
}
......@@ -1253,7 +1258,7 @@ static size_t get_prev_slot(const struct elphel_ahci_priv *dpriv)
return slot;
}
/** Handle delayed interrupt or ather errors */
/** Handle delayed interrupt or other errors */
void error_handler(struct elphel_ahci_priv *dpriv)
{
long rc;
......@@ -1272,27 +1277,25 @@ void error_handler(struct elphel_ahci_priv *dpriv)
}
rc = wait_event_interruptible_timeout(dpriv->eh.wait, dpriv->flags & DELAYED_IRQ_RCVD, deadline);
dev_warn(dpriv->dev, "wait_event_interruptible_timeout returned %ld\n", rc);
dev_dbg(dpriv->dev, "wait_event_interruptible_timeout returned %ld\n", rc);
if (!rc) {
return;
// reset_flag(dpriv, IRQ_SIMPLE | DISK_BUSY | PROC_CMD | START_EH);
// /* interrupt has not been received after more than (DEFAULT_CMD_TIMEOUT + WAIT_IRQ_TIMEOUT) ms,
// * try to recover the link using WAIT_IRQ_TIMEOUT value for next deadline
// */
// deadline = jiffies + msecs_to_jiffies(WAIT_IRQ_TIMEOUT);
// rc = ap->ops->hardreset(link, &class, deadline);
// if (!rc)
// dev_err(dpriv->dev, "error: ahci_hardreset returned %ld\n", rc);
// ata_port_wait_eh(ap);
//
// // here we assume that circbuf has not been overrun yet, prepare to repeat current command
// dpriv->lba_ptr.wr_count = 0;
// dpriv->curr_cmd = 0;
// dpriv->max_data_sz = 0;
// dpriv->curr_data_chunk = 0;
// dpriv->curr_data_offset = 0;
reset_flag(dpriv, IRQ_SIMPLE | DISK_BUSY | PROC_CMD | START_EH);
/* interrupt has not been received after more than (DEFAULT_CMD_TIMEOUT + WAIT_IRQ_TIMEOUT) ms,
* try to recover the link using WAIT_IRQ_TIMEOUT value for next deadline
*/
deadline = jiffies + msecs_to_jiffies(WAIT_IRQ_TIMEOUT);
rc = ap->ops->hardreset(link, &class, deadline);
if (!rc)
dev_err(dpriv->dev, "error: ahci_hardreset returned %ld\n", rc);
ata_port_wait_eh(ap);
// here we assume that circbuf has not been overrun yet, prepare to repeat current command
dpriv->lba_ptr.wr_count = 0;
dpriv->curr_cmd = 0;
dpriv->max_data_sz = 0;
dpriv->curr_data_chunk = 0;
dpriv->curr_data_offset = 0;
dev_dbg(dpriv->dev, "repeat command from slot (head_ptr): %u\n", dpriv->head_ptr);
// process_cmd(dpriv);
} else {
// late interrupt received or the queue was woken up, proceed to normal operation
if (rc < 0) {
......@@ -1302,7 +1305,7 @@ void error_handler(struct elphel_ahci_priv *dpriv)
}
dpriv->stat.last_irq_delay = jiffies_to_msecs(delay) + DEFAULT_CMD_TIMEOUT;
dpriv->stat.stat_ready = 1;
dev_warn(dpriv->dev, "late interrupt received, delay is %lu ms\n", dpriv->stat.last_irq_delay);
dev_dbg(dpriv->dev, "late interrupt received, delay is %lu ms\n", dpriv->stat.last_irq_delay);
reset_flag(dpriv, DELAYED_IRQ_RCVD | START_EH);
}
reset_flag(dpriv, WAIT_EH);
......@@ -1581,8 +1584,6 @@ static int elphel_qc_defer(struct ata_queued_cmd *qc)
unsigned long irq_flags;
struct elphel_ahci_priv *dpriv = dev_get_dpriv(qc->ap->dev);
dev_dbg(qc->ap->dev, "flags: %u\n", dpriv->flags);
/* First apply the usual rules */
ret = ata_std_qc_defer(qc);
if (ret != 0)
......@@ -1948,24 +1949,13 @@ static void set_dscope_tstamp(struct elphel_ahci_priv *dpriv, unsigned int cmd)
void __iomem *port_mmio;
uint32_t data = 0;
// if (!dpriv->datascope.enable)
// return;
host = dev_get_drvdata(dpriv->dev);
hpriv = host->private_data;
ap = host->ports[DEFAULT_PORT_NUM];
port_mmio = ahci_port_base(ap);
// one bit command flag (TSTMP_*)
// three bits command flag (TSTMP_*)
data |= (cmd & 0x7);
// command counter
// data |= ((dpriv->datascope.cmd_cntr & 0x3) << 1);
// if (cmd == TSTMP_IRQ_RCVD) {
// dpriv->datascope.cmd_cntr++;
// if (dpriv->datascope.cmd_cntr > 3)
// dpriv->datascope.cmd_cntr = 0;
// }
iowrite32(data, port_mmio + PORT_TIMESTAMP_ADDR);
}
......
src/drivers/ata/ahci_elphel.h
View file @ d6018112
......@@ -40,6 +40,7 @@
#define START_EH (1 << 6) ///< Start error handling procedure
#define WAIT_EH (1 << 7) ///< Wait for error handler completion
#define DELAYED_IRQ_RCVD (1 << 8) ///< Delayed interrupt received and should be processed
#define IRQ_PROCESSED (1 << 9) ///< Tell command guard timer that IRQ is received and EH should not be started
#define CMD_FIS_LEN 5 ///< The length of a command FIS in double words
#define ADDR_MASK_28_BIT ((u64)0xfffffff)///< This is used to get 28-bit address from 64-bit value
#define MAX_PRDT_LEN 0x3fffff ///< A maximum of length of 4MB may exist for PRDT entry
......@@ -62,17 +63,17 @@
#define INCLUDE_REM 1 ///< Include REM buffer to total size calculation
#define EXCLUDE_REM 0 ///< Exclude REM buffer from total size calculation
#define SPEED_SAMPLES_NUM 5 ///< Maximum number of samples for disk recording speed measurement
#define DEFAULT_CMD_TIMEOUT 100 ///< Default timeout for commands, in ms
#define DEFAULT_CMD_TIMEOUT 200 ///< Default timeout for commands, in ms
#define WAIT_IRQ_TIMEOUT 5000 ///< Wait delayed interrupt for this amount of time, in ms
#define TSTMP_CMD_SYS 1 ///< command issued by system
#define TSTMP_CMD_DRV 2 ///< command issued by driver
#define TSTMP_IRQ_SYS 3 ///< irq processed by system
#define TSTMP_IRQ_DRV 4 ///< irq processed by driver
#define TSTMP_IRQ_MARK_1 5
#define TSTMP_IRQ_MARK_1 5 ///< additional time stamp mark
enum {
PORT_VS = 0x70, ///< vendor specific port address
PORT_TIMESTAMP_ADDR = 0x78 ///< datascope timestamp register
PORT_VS = 0x70, ///< vendor specific port address
PORT_TIMESTAMP_ADDR = 0x78 ///< datascope timestamp register
};
enum {
REG_NUM = 128, ///< total number of DWs in status buffer
......@@ -93,8 +94,8 @@ struct datascope {
/** Data for error handler */
struct error_handler {
uint32_t s_error;
uint32_t irq_stat;
uint32_t s_error; ///< the content of PxSERR register
uint32_t irq_stat; ///< the content of PxIS register
wait_queue_head_t wait; ///< wait queue for delayed interrupts
};
......@@ -105,7 +106,7 @@ struct rec_stat {
///< presented via sysfs is a median of this array
sec_usec_t start_time; ///< time when current command has been issued
unsigned long last_irq_delay; ///< late interrupt delay, in ms
unsigned int stat_ready; ///< flag indicating that new statisics sample is ready
unsigned int stat_ready; ///< flag indicating that new statisics sample is ready
};
/** This structure holds raw device buffer pointers */
......
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