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authorSerge Semin <fancer.lancer@gmail.com>2018-07-17 11:24:36 +0200
committerJon Mason <jdmason@kudzu.us>2018-11-01 15:33:12 +0100
commitb8babacbae624da6d244d0721263edda56be3991 (patch)
treed52389c295510d0fdf3110927bad82f7d98b7210 /drivers/ntb
parentntb: idt: Add basic hwmon sysfs interface (diff)
downloadlinux-b8babacbae624da6d244d0721263edda56be3991.tar.xz
linux-b8babacbae624da6d244d0721263edda56be3991.zip
ntb: idt: Discard temperature sensor IRQ handler
IDT PCIe-switch temperature sensor interface is very broken. First of all only a few combinations of TMPCTL threshold enable bits really cause the interrupts unmasked. Even if an individual bit indicates the event unmasked, corresponding IRQ just isn't generated. Most of the threshold enable bits combinations are in fact useless and non of them can help to create a fully functional alarm interface. So to speak, we can't create a well defined hwmon alarms based on the IDT PCI-switch threshold IRQs. Secondly a single threshold IRQ (not a combination of thresholds) can be successfully enabled without the issue described above. But in this case we experienced an enormous number of interrupts generated by the chip if the temperature got near the enabled threshold value. Filter adjustment didn't help much. It also doesn't provide a hysteresis settings. Due to the temperature sample fluctuations near the threshold the interrupts spate makes the system nearly unusable until the temperature value finally settled so being pushed either to be fully higher or lower the threshold. All of these issues makes the temperature sensor alarm interface useless and even at some point dangerous to be used in the driver. In this case it is safer to completely discard it and disable the temperature alarm interrupts. Signed-off-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
Diffstat (limited to 'drivers/ntb')
-rw-r--r--drivers/ntb/hw/idt/ntb_hw_idt.c41
-rw-r--r--drivers/ntb/hw/idt/ntb_hw_idt.h5
2 files changed, 3 insertions, 43 deletions
diff --git a/drivers/ntb/hw/idt/ntb_hw_idt.c b/drivers/ntb/hw/idt/ntb_hw_idt.c
index 19425a2c60cd..c4594a708b48 100644
--- a/drivers/ntb/hw/idt/ntb_hw_idt.c
+++ b/drivers/ntb/hw/idt/ntb_hw_idt.c
@@ -2075,38 +2075,6 @@ static struct attribute *idt_temp_attrs[] = {
ATTRIBUTE_GROUPS(idt_temp);
/*
- * idt_temp_isr() - temperature sensor alarm events ISR
- * @ndev: IDT NTB hardware driver descriptor
- * @ntint_sts: NT-function interrupt status
- *
- * It handles events of temperature crossing alarm thresholds. Since reading
- * of TMPALARM register clears it up, the function doesn't analyze the
- * read value, instead the current temperature value just warningly printed to
- * log.
- * The method is called from PCIe ISR bottom-half routine.
- */
-static void idt_temp_isr(struct idt_ntb_dev *ndev, u32 ntint_sts)
-{
- unsigned long mdeg;
-
- /* Read the current temperature value */
- idt_read_temp(ndev, IDT_TEMP_CUR, &mdeg);
-
- /* Read the temperature alarm to clean the alarm status out */
- /*(void)idt_sw_read(ndev, IDT_SW_TMPALARM);*/
-
- /* Clean the corresponding interrupt bit */
- idt_nt_write(ndev, IDT_NT_NTINTSTS, IDT_NTINTSTS_TMPSENSOR);
-
- dev_dbg(&ndev->ntb.pdev->dev,
- "Temp sensor IRQ detected %#08x", ntint_sts);
-
- /* Print temperature value to log */
- dev_warn(&ndev->ntb.pdev->dev, "Temperature %hhd.%hhuC",
- idt_get_deg(mdeg), idt_get_deg_frac(mdeg));
-}
-
-/*
* idt_init_temp() - initialize temperature sensor interface
* @ndev: IDT NTB hardware driver descriptor
*
@@ -2188,7 +2156,7 @@ static int idt_init_isr(struct idt_ntb_dev *ndev)
goto err_free_vectors;
}
- /* Unmask Message/Doorbell/SE/Temperature interrupts */
+ /* Unmask Message/Doorbell/SE interrupts */
ntint_mask = idt_nt_read(ndev, IDT_NT_NTINTMSK) & ~IDT_NTINTMSK_ALL;
idt_nt_write(ndev, IDT_NT_NTINTMSK, ntint_mask);
@@ -2203,7 +2171,6 @@ err_free_vectors:
return ret;
}
-
/*
* idt_deinit_ist() - deinitialize PCIe interrupt handler
* @ndev: IDT NTB hardware driver descriptor
@@ -2264,12 +2231,6 @@ static irqreturn_t idt_thread_isr(int irq, void *devid)
handled = true;
}
- /* Handle temperature sensor interrupt */
- if (ntint_sts & IDT_NTINTSTS_TMPSENSOR) {
- idt_temp_isr(ndev, ntint_sts);
- handled = true;
- }
-
dev_dbg(&ndev->ntb.pdev->dev, "IDT IRQs 0x%08x handled", ntint_sts);
return handled ? IRQ_HANDLED : IRQ_NONE;
diff --git a/drivers/ntb/hw/idt/ntb_hw_idt.h b/drivers/ntb/hw/idt/ntb_hw_idt.h
index 032f81cb4d44..3517cd2e2baa 100644
--- a/drivers/ntb/hw/idt/ntb_hw_idt.h
+++ b/drivers/ntb/hw/idt/ntb_hw_idt.h
@@ -688,15 +688,14 @@
* @IDT_NTINTMSK_DBELL: Doorbell interrupt mask bit
* @IDT_NTINTMSK_SEVENT: Switch Event interrupt mask bit
* @IDT_NTINTMSK_TMPSENSOR: Temperature sensor interrupt mask bit
- * @IDT_NTINTMSK_ALL: All the useful interrupts mask
+ * @IDT_NTINTMSK_ALL: NTB-related interrupts mask
*/
#define IDT_NTINTMSK_MSG 0x00000001U
#define IDT_NTINTMSK_DBELL 0x00000002U
#define IDT_NTINTMSK_SEVENT 0x00000008U
#define IDT_NTINTMSK_TMPSENSOR 0x00000080U
#define IDT_NTINTMSK_ALL \
- (IDT_NTINTMSK_MSG | IDT_NTINTMSK_DBELL | \
- IDT_NTINTMSK_SEVENT | IDT_NTINTMSK_TMPSENSOR)
+ (IDT_NTINTMSK_MSG | IDT_NTINTMSK_DBELL | IDT_NTINTMSK_SEVENT)
/*
* NTGSIGNAL register fields related constants