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* [PATCH v2] ARM: s3c: irq-s3c24xx: Fix return value check for s3c24xx_init_intc()
@ 2021-09-01 12:35 Jackie Liu
  2021-09-06 10:23 ` Jackie Liu
                   ` (2 more replies)
  0 siblings, 3 replies; 7+ messages in thread
From: Jackie Liu @ 2021-09-01 12:35 UTC (permalink / raw)
  To: krzysztof.kozlowski
  Cc: linux-samsung-soc, linux-arm-kernel, liu.yun, liuyun01

From: Jackie Liu <liuyun01@kylinos.cn>

The s3c24xx_init_intc() returns an error pointer upon failure, not NULL.
let's add an error pointer check in s3c24xx_handle_irq.

s3c_intc[0] is not NULL or ERR, we can simplify the code.

Fixes: 1f629b7a3ced ("ARM: S3C24XX: transform irq handling into a declarative form")
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
---
 arch/arm/mach-s3c/irq-s3c24xx.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/arch/arm/mach-s3c/irq-s3c24xx.c b/arch/arm/mach-s3c/irq-s3c24xx.c
index 0c631c14a817..df471d322493 100644
--- a/arch/arm/mach-s3c/irq-s3c24xx.c
+++ b/arch/arm/mach-s3c/irq-s3c24xx.c
@@ -362,11 +362,24 @@ static inline int s3c24xx_handle_intc(struct s3c_irq_intc *intc,
 static asmlinkage void __exception_irq_entry s3c24xx_handle_irq(struct pt_regs *regs)
 {
 	do {
-		if (likely(s3c_intc[0]))
-			if (s3c24xx_handle_intc(s3c_intc[0], regs, 0))
-				continue;
+		/* For platform based machines, neither ERR nor NULL can happen here.
+		 * The s3c24xx_handle_irq() will be set as IRQ handler iff this succeeds:
+		 *
+		 *    s3c_intc[0] = s3c24xx_init_intc()
+		 *
+		 * If this fails, the next calls to s3c24xx_init_intc() won't be executed.
+		 *
+		 * For DT machine, s3c_init_intc_of() could set the IRQ handler without
+		 * setting s3c_intc[0] only if it was called with num_ctrl=0. There is no
+		 * such code path, so again the s3c_intc[0] will have a valid pointer if
+		 * set_handle_irq() is called.
+		 *
+		 * Therefore in s3c24xx_handle_irq(), the s3c_intc[0] is always something.
+		 */
+		if (s3c24xx_handle_intc(s3c_intc[0], regs, 0))
+			continue;
 
-		if (s3c_intc[2])
+		if (!IS_ERR_OR_NULL(s3c_intc[2]))
 			if (s3c24xx_handle_intc(s3c_intc[2], regs, 64))
 				continue;
 
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2021-10-26 15:29 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-01 12:35 [PATCH v2] ARM: s3c: irq-s3c24xx: Fix return value check for s3c24xx_init_intc() Jackie Liu
2021-09-06 10:23 ` Jackie Liu
2021-09-06 10:52   ` Krzysztof Kozlowski
2021-09-15  7:50 ` Krzysztof Kozlowski
2021-10-26 15:10 ` Arnd Bergmann
2021-10-26 15:22   ` Krzysztof Kozlowski
2021-10-26 15:28     ` Arnd Bergmann

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