Re: [PATCH v2 2/3] pwm: bcm2835: allow pwm driver to be used in atomic context
From: Ivaylo Dimitrov <hidden>
Date: 2023-10-14 06:51:33
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On 13.10.23 г. 20:51 ч., Uwe Kleine-König wrote:
Hello, On Fri, Oct 13, 2023 at 01:13:50PM +0200, Alexander Stein wrote:quoted
Am Freitag, 13. Oktober 2023, 13:04:48 CEST schrieb Stefan Wahren:quoted
Am 13.10.23 um 12:46 schrieb Sean Young:quoted
clk_get_rate() may do a mutex lock. Since the clock rate cannot change on an rpi, simply fetch it once.does it mean you checked all possible SoCs (BCM2835, BCM2836, BCM2837, BCM2711, BCM2712) for this change? Is it impossible that the real clock can never be influenced by turbo mode like SPI?Assuming the clock can change, which I would, then a clock notifier seems appropriate. See [1] for an example.I'm not a fan. If the clock changes, the output also changes. With a clock notifier you can soften the issue and reconfigure to something similar as the original wave form, but a glitch happens for sure.
Right, but without notifier, everything rate related after the change will be wrong Ivo _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel