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From: Bartosz Golaszewski <brgl@bgdev.pl>
To: Kent Gibson <warthog618@gmail.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-gpio@vger.kernel.org,
	Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Subject: [libgpiod][PATCH 2/2] bindings: cxx: examples: fix potential glitch in gpiosetcxx
Date: Mon, 12 Jun 2023 16:56:53 +0200	[thread overview]
Message-ID: <20230612145653.138615-3-brgl@bgdev.pl> (raw)
In-Reply-To: <20230612145653.138615-1-brgl@bgdev.pl>

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

gpiosetcxx requests lines without setting their output value, and so
sets them all inactive, and subsequently sets them to their requested
value. This can result in glitches on lines which were active and
are set active.

As this is example code, it is also important to demonstrate that the
output value can be set by the request itself.

Request the lines with the correct output values set in the request
itself.

Suggested-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 bindings/cxx/examples/gpiosetcxx.cpp | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/bindings/cxx/examples/gpiosetcxx.cpp b/bindings/cxx/examples/gpiosetcxx.cpp
index dde5379..f46cb85 100644
--- a/bindings/cxx/examples/gpiosetcxx.cpp
+++ b/bindings/cxx/examples/gpiosetcxx.cpp
@@ -44,10 +44,9 @@ int main(int argc, char **argv)
 			::gpiod::line_settings()
 				.set_direction(::gpiod::line::direction::OUTPUT)
 		)
+		.set_output_values(values)
 		.do_request();
 
-	request.set_values(values);
-
 	::std::cin.get();
 
 	return EXIT_SUCCESS;
-- 
2.39.2


  parent reply	other threads:[~2023-06-12 14:57 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-12 14:56 [libgpiod][PATCH 0/2] bindings: cxx: fix potential glitch in gpiosetcxx Bartosz Golaszewski
2023-06-12 14:56 ` [libgpiod][PATCH 1/2] bindings: cxx: provide request_builder::set_output_values() Bartosz Golaszewski
2023-06-12 14:56 ` Bartosz Golaszewski [this message]
2023-06-12 15:06 ` [libgpiod][PATCH 0/2] bindings: cxx: fix potential glitch in gpiosetcxx Kent Gibson
  -- strict thread matches above, loose matches on Subject: below --
2023-06-09 15:36 [libgpiod][PATCH 0/2] fix potential glitches in bindings example gpiosets Kent Gibson
2023-06-09 15:36 ` [libgpiod][PATCH 2/2] bindings: cxx: examples: fix potential glitch in gpiosetcxx Kent Gibson
2023-06-09 20:19   ` andy.shevchenko

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