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Miller" , Frank Wunderlich , =?iso-8859-1?Q?Ren=E9?= van Dorst , Rob Herring , "moderated list:ARM/Mediatek SoC support" , Philipp Zabel , Matthias Brugger , Jakub Kicinski , Vladimir Oltean , Vivien Didelot , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Jan 11, 2021 at 09:40:00PM +0800, DENG Qingfang wrote: > On Mon, Jan 11, 2021 at 7:04 PM Russell King - ARM Linux admin > wrote: > > > > FYI, Documentation/driver-api/gpio/consumer.rst says: > > > > For output GPIOs, the value provided becomes the initial output value. > > This helps avoid signal glitching during system startup. > > > > Setting the pin to be an output, and then setting its initial value > > does not avoid the glitch. You may wish to investigate whether you > > can set the value before setting the pin as an output to avoid this > > issue. > > > > So, setting the Output Enable bit _after_ setting the direction and > initial value should avoid this issue. Right? It depends on the hardware. I don't know how your hardware works, so I can't say whether doing anything will result in correct behaviour, or even work. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel