* [PATCH 0/2] watchdog: sama5d4: fix IRQ and timeout bugs, use platform_get_irq_optional
@ 2026-06-04 1:05 Rosen Penev
2026-06-04 1:05 ` [PATCH 1/2] watchdog: sama5d4: fix shared IRQ and hardcoded timeout issues Rosen Penev
2026-06-04 1:05 ` [PATCH 2/2] watchdog: sama5d4: use platform_get_irq_optional() Rosen Penev
0 siblings, 2 replies; 3+ messages in thread
From: Rosen Penev @ 2026-06-04 1:05 UTC (permalink / raw)
To: linux-watchdog
Cc: Nicolas Ferre, Alexandre Belloni, Claudiu Beznea,
Wim Van Sebroeck, Guenter Roeck,
moderated list:ARM/Microchip (AT91) SoC support, open list
This series fixes three pre-existing issues in the sama5d4 watchdog
driver (unsafe IRQF_SHARED, incorrect IRQ_HANDLED return, ignored
device-tree timeout), then simplifies interrupt acquisition by
switching from irq_of_parse_and_map() to platform_get_irq_optional().
Rosen Penev (2):
watchdog: sama5d4: fix shared IRQ and hardcoded timeout issues
watchdog: sama5d4: use platform_get_irq_optional()
drivers/watchdog/sama5d4_wdt.c | 33 ++++++++++++++++++---------------
1 file changed, 18 insertions(+), 15 deletions(-)
--
2.54.0
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH 1/2] watchdog: sama5d4: fix shared IRQ and hardcoded timeout issues
2026-06-04 1:05 [PATCH 0/2] watchdog: sama5d4: fix IRQ and timeout bugs, use platform_get_irq_optional Rosen Penev
@ 2026-06-04 1:05 ` Rosen Penev
2026-06-04 1:05 ` [PATCH 2/2] watchdog: sama5d4: use platform_get_irq_optional() Rosen Penev
1 sibling, 0 replies; 3+ messages in thread
From: Rosen Penev @ 2026-06-04 1:05 UTC (permalink / raw)
To: linux-watchdog
Cc: Nicolas Ferre, Alexandre Belloni, Claudiu Beznea,
Wim Van Sebroeck, Guenter Roeck,
moderated list:ARM/Microchip (AT91) SoC support, open list
Fix three pre-existing issues in the sama5d4 watchdog driver:
1. Unsafe IRQF_SHARED | IRQF_NO_SUSPEND combination: The watchdog
interrupt is a dedicated peripheral line, not shared with other
devices. Drop IRQF_SHARED to avoid the documented unsafe interaction
where IRQF_NO_SUSPEND keeps the line enabled during suspend while
other sharing devices may be powered down.
2. Unconditional IRQ_HANDLED on shared line: The handler returned
IRQ_HANDLED even when the status register indicated no watchdog
interrupt was pending. Return IRQ_NONE in that case so the kernel
can properly detect spurious interrupts on the line.
3. Hardcoded 16-second timeout: sama5d4_wdt_init() unconditionally
used WDT_DEFAULT_TIMEOUT (16s) for the hardware timeout, ignoring
any timeout configured via device tree (watchdog_init_timeout) or
userspace. Pass wdd->timeout to sama5d4_wdt_init() so the
configured timeout is honored during probe and resume.
Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail•com>
---
drivers/watchdog/sama5d4_wdt.c | 23 ++++++++++++-----------
1 file changed, 12 insertions(+), 11 deletions(-)
diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c
index 704b786cc2ec..b7a8cfed335d 100644
--- a/drivers/watchdog/sama5d4_wdt.c
+++ b/drivers/watchdog/sama5d4_wdt.c
@@ -169,11 +169,12 @@ static irqreturn_t sama5d4_wdt_irq_handler(int irq, void *dev_id)
else
reg = wdt_read(wdt, AT91_WDT_SR);
- if (reg) {
- pr_crit("Atmel Watchdog Software Reset\n");
- emergency_restart();
- pr_crit("Reboot didn't succeed\n");
- }
+ if (!reg)
+ return IRQ_NONE;
+
+ pr_crit("Atmel Watchdog Software Reset\n");
+ emergency_restart();
+ pr_crit("Reboot didn't succeed\n");
return IRQ_HANDLED;
}
@@ -197,11 +198,11 @@ static int of_sama5d4_wdt_init(struct device_node *np, struct sama5d4_wdt *wdt)
return 0;
}
-static int sama5d4_wdt_init(struct sama5d4_wdt *wdt)
+static int sama5d4_wdt_init(struct sama5d4_wdt *wdt, unsigned int timeout)
{
u32 reg, val;
- val = WDT_SEC2TICKS(WDT_DEFAULT_TIMEOUT);
+ val = WDT_SEC2TICKS(timeout);
/*
* When booting and resuming, the bootloader may have changed the
* watchdog configuration.
@@ -289,8 +290,8 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
if (wdt->need_irq) {
ret = devm_request_irq(dev, irq, sama5d4_wdt_irq_handler,
- IRQF_SHARED | IRQF_IRQPOLL |
- IRQF_NO_SUSPEND, pdev->name, pdev);
+ IRQF_IRQPOLL | IRQF_NO_SUSPEND,
+ pdev->name, pdev);
if (ret) {
dev_err(dev, "cannot register interrupt handler\n");
return ret;
@@ -305,7 +306,7 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
set_bit(WDOG_HW_RUNNING, &wdd->status);
}
- ret = sama5d4_wdt_init(wdt);
+ ret = sama5d4_wdt_init(wdt, wdd->timeout);
if (ret)
return ret;
@@ -358,7 +359,7 @@ static int sama5d4_wdt_resume_early(struct device *dev)
* This should only be done when the registers are lost on suspend but
* there is no way to get this information right now.
*/
- sama5d4_wdt_init(wdt);
+ sama5d4_wdt_init(wdt, wdt->wdd.timeout);
if (watchdog_active(&wdt->wdd))
sama5d4_wdt_start(&wdt->wdd);
--
2.54.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 2/2] watchdog: sama5d4: use platform_get_irq_optional()
2026-06-04 1:05 [PATCH 0/2] watchdog: sama5d4: fix IRQ and timeout bugs, use platform_get_irq_optional Rosen Penev
2026-06-04 1:05 ` [PATCH 1/2] watchdog: sama5d4: fix shared IRQ and hardcoded timeout issues Rosen Penev
@ 2026-06-04 1:05 ` Rosen Penev
1 sibling, 0 replies; 3+ messages in thread
From: Rosen Penev @ 2026-06-04 1:05 UTC (permalink / raw)
To: linux-watchdog
Cc: Nicolas Ferre, Alexandre Belloni, Claudiu Beznea,
Wim Van Sebroeck, Guenter Roeck,
moderated list:ARM/Microchip (AT91) SoC support, open list
irq_of_parse_and_map() requires irq_dispose_mapping() on failure. Don't
bother with it as platform_get_irq_optional() doesn't need it.
Also handle EPROBE_DEFER.
Signed-off-by: Rosen Penev <rosenp@gmail•com>
---
drivers/watchdog/sama5d4_wdt.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c
index b7a8cfed335d..030029d50257 100644
--- a/drivers/watchdog/sama5d4_wdt.c
+++ b/drivers/watchdog/sama5d4_wdt.c
@@ -11,7 +11,6 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
-#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/watchdog.h>
@@ -245,7 +244,7 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
struct watchdog_device *wdd;
struct sama5d4_wdt *wdt;
void __iomem *regs;
- u32 irq = 0;
+ int irq = 0;
u32 reg;
int ret;
@@ -281,8 +280,11 @@ static int sama5d4_wdt_probe(struct platform_device *pdev)
return ret;
if (wdt->need_irq) {
- irq = irq_of_parse_and_map(dev->of_node, 0);
- if (!irq) {
+ irq = platform_get_irq_optional(pdev, 0);
+ if (irq == -EPROBE_DEFER)
+ return irq;
+
+ if (irq < 0) {
dev_warn(dev, "failed to get IRQ from DT\n");
wdt->need_irq = false;
}
--
2.54.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-06-04 1:06 UTC | newest]
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2026-06-04 1:05 [PATCH 0/2] watchdog: sama5d4: fix IRQ and timeout bugs, use platform_get_irq_optional Rosen Penev
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