Re: [PATCH v1 1/1] regmap-irq: Consistently use memset32() in regmap_irq_thread()

From: Matti Vaittinen
Date: Wed Sep 25 2024 - 04:56:01 EST


On 9/25/24 11:27, Andy Shevchenko wrote:
The commit 4d60cac951fd ("regmap-irq: Add no_status support") adds
an additional branch into IRQ thread handler in regmap. It wisely
chose to use memset32() as it might be optimised on some architectures
and hence give a performance benefit. At the same time the old code
continue using simple memset(). Update the old code to use memset32().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/base/regmap/regmap-irq.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
index a750e48a26b8..33ec28e3a802 100644
--- a/drivers/base/regmap/regmap-irq.c
+++ b/drivers/base/regmap/regmap-irq.c
@@ -364,14 +364,11 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
memset32(data->status_buf, GENMASK(31, 0), chip->num_regs);
} else if (chip->num_main_regs) {
unsigned int max_main_bits;
- unsigned long size;
-
- size = chip->num_regs * sizeof(unsigned int);
max_main_bits = (chip->num_main_status_bits) ?
chip->num_main_status_bits : chip->num_regs;
/* Clear the status buf as we don't read all status regs */
- memset(data->status_buf, 0, size);
+ memset32(data->status_buf, 0, chip->num_regs);
/* We could support bulk read for main status registers
* but I don't expect to see devices with really many main

Thanks Andy.

Can we guarantee the sizeof(unsigned int) == sizeof(uint32_t) on all supported architectures? (The status_buf is unsigned int, right?). If yes, then this looks nice to me.

Yours,
-- Matti

--
Matti Vaittinen
Linux kernel developer at ROHM Semiconductors
Oulu Finland

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