Tasklets have long been deprecated as being too heavy on the system
by running in irq context - and this is not a performance critical
path. If a higher priority process wants to run, it must wait for
the tasklet to finish before doing so. A more suitable equivalent
is to converted to threaded irq instead.
As such remove CONFIG_SCSI_MVSAS_TASKLET (which is horrible to begin
with) and continue to do the async work, unconditionally now, just
in task context. Just as with the tasklet version, device interrupts
(MVS_IRQ_SAS_A/B) continues to be disabled from when the work was
putted until it is actually complete. Because there are no guarantees
vs ksoftirqd, if this is broken for threaded irqs, then they are
also broken for tasklets.
Signed-off-by: Davidlohr Bueso <dave@xxxxxxxxxxxx>
---
drivers/scsi/mvsas/Kconfig | 7 ------
drivers/scsi/mvsas/mv_init.c | 44 ++++++------------------------------
drivers/scsi/mvsas/mv_sas.h | 1 -
3 files changed, 7 insertions(+), 45 deletions(-)
diff --git a/drivers/scsi/mvsas/Kconfig b/drivers/scsi/mvsas/Kconfig
index 79812b80743b..e9dd8dc84b1c 100644
--- a/drivers/scsi/mvsas/Kconfig
+++ b/drivers/scsi/mvsas/Kconfig
@@ -23,10 +23,3 @@ config SCSI_MVSAS_DEBUG
help
Compiles the 88SE64XX/88SE94XX driver in debug mode. In debug mode,
the driver prints some messages to the console.
-config SCSI_MVSAS_TASKLET
- bool "Support for interrupt tasklet"
- default n
- depends on SCSI_MVSAS
- help
- Compiles the 88SE64xx/88SE94xx driver in interrupt tasklet mode.In this mode,
- the interrupt will schedule a tasklet.
diff --git a/drivers/scsi/mvsas/mv_init.c b/drivers/scsi/mvsas/mv_init.c
index 2fde496fff5f..f36b270ba502 100644
--- a/drivers/scsi/mvsas/mv_init.c
+++ b/drivers/scsi/mvsas/mv_init.c
@@ -146,12 +146,10 @@ static void mvs_free(struct mvs_info *mvi)
kfree(mvi);
}
-#ifdef CONFIG_SCSI_MVSAS_TASKLET
-static void mvs_tasklet(unsigned long opaque)
+static irqreturn_t mvs_async(int irq, void *opaque)
{
u32 stat;
u16 core_nr, i = 0;
-
struct mvs_info *mvi;
struct sas_ha_struct *sha = (struct sas_ha_struct *)opaque;
@@ -172,46 +170,29 @@ static void mvs_tasklet(unsigned long opaque)
out:
MVS_CHIP_DISP->interrupt_enable(mvi);
+ return IRQ_HANDLED;
}
-#endif
static irqreturn_t mvs_interrupt(int irq, void *opaque)
{
u32 stat;
struct mvs_info *mvi;
struct sas_ha_struct *sha = opaque;
-#ifndef CONFIG_SCSI_MVSAS_TASKLET
- u32 i;
- u32 core_nr;
-
- core_nr = ((struct mvs_prv_info *)sha->lldd_ha)->n_host;
-#endif
mvi = ((struct mvs_prv_info *)sha->lldd_ha)->mvi[0];
if (unlikely(!mvi))
return IRQ_NONE;
-#ifdef CONFIG_SCSI_MVSAS_TASKLET
+
MVS_CHIP_DISP->interrupt_disable(mvi);
-#endif
stat = MVS_CHIP_DISP->isr_status(mvi, irq);
if (!stat) {
- #ifdef CONFIG_SCSI_MVSAS_TASKLET
MVS_CHIP_DISP->interrupt_enable(mvi);
- #endif
return IRQ_NONE;
}
-#ifdef CONFIG_SCSI_MVSAS_TASKLET
- tasklet_schedule(&((struct mvs_prv_info *)sha->lldd_ha)->mv_tasklet);
-#else
- for (i = 0; i < core_nr; i++) {
- mvi = ((struct mvs_prv_info *)sha->lldd_ha)->mvi[i];
- MVS_CHIP_DISP->isr(mvi, irq, stat);
- }
-#endif
- return IRQ_HANDLED;
+ return IRQ_WAKE_THREAD;
}
static int mvs_alloc(struct mvs_info *mvi, struct Scsi_Host *shost)
@@ -557,14 +538,6 @@ static int mvs_pci_init(struct pci_dev *pdev, const struct pci_device_id *ent)
}
nhost++;
} while (nhost < chip->n_host);
-#ifdef CONFIG_SCSI_MVSAS_TASKLET
- {
- struct mvs_prv_info *mpi = SHOST_TO_SAS_HA(shost)->lldd_ha;
-
- tasklet_init(&(mpi->mv_tasklet), mvs_tasklet,
- (unsigned long)SHOST_TO_SAS_HA(shost));
- }
-#endif
mvs_post_sas_ha_init(shost, chip);
@@ -575,8 +548,9 @@ static int mvs_pci_init(struct pci_dev *pdev, const struct pci_device_id *ent)
rc = sas_register_ha(SHOST_TO_SAS_HA(shost));
if (rc)
goto err_out_shost;
- rc = request_irq(pdev->irq, irq_handler, IRQF_SHARED,
- DRV_NAME, SHOST_TO_SAS_HA(shost));
+ rc = request_threaded_irq(pdev->irq, irq_handler, mvs_async,
+ IRQF_SHARED, DRV_NAME,
+ SHOST_TO_SAS_HA(shost));
if (rc)
goto err_not_sas;
@@ -607,10 +581,6 @@ static void mvs_pci_remove(struct pci_dev *pdev)
core_nr = ((struct mvs_prv_info *)sha->lldd_ha)->n_host;
mvi = ((struct mvs_prv_info *)sha->lldd_ha)->mvi[0];
-#ifdef CONFIG_SCSI_MVSAS_TASKLET
- tasklet_kill(&((struct mvs_prv_info *)sha->lldd_ha)->mv_tasklet);
-#endif
-
sas_unregister_ha(sha);
sas_remove_host(mvi->shost);
diff --git a/drivers/scsi/mvsas/mv_sas.h b/drivers/scsi/mvsas/mv_sas.h
index 509d8f32a04f..a0e87fdab98a 100644
--- a/drivers/scsi/mvsas/mv_sas.h
+++ b/drivers/scsi/mvsas/mv_sas.h
@@ -403,7 +403,6 @@ struct mvs_prv_info{
u8 scan_finished;
u8 reserve;
struct mvs_info *mvi[2];
- struct tasklet_struct mv_tasklet;
};
struct mvs_wq {
--
2.36.1
