> -----Original Message----- > From: Mark Brown <broonie@xxxxxxxxxx> > Sent: 24 February 2022 23:52 > To: Krishna Yarlagadda <kyarlagadda@xxxxxxxxxx> > Cc: thierry.reding@xxxxxxxxx; Jonathan Hunter <jonathanh@xxxxxxxxxx>; linux-spi@xxxxxxxxxxxxxxx; linux-tegra@xxxxxxxxxxxxxxx; > Sowjanya Komatineni <skomatineni@xxxxxxxxxx>; Laxman Dewangan <ldewangan@xxxxxxxxxx>; robh+dt@xxxxxxxxxx; > devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; p.zabel@xxxxxxxxxxxxxx > Subject: Re: [PATCH v2 4/5] spi: tegra210-quad: add acpi support > > On Wed, Feb 23, 2022 at 06:32:56AM +0000, Krishna Yarlagadda wrote: > > > > > + if (has_acpi_companion(tqspi->dev)) > > > > + return 0; > > > > /* flush all write which are in PPSB queue by reading back */ > > > > tegra_qspi_readl(tqspi, QSPI_COMMAND1); > > > > As well as clock stuff this is also skipping flushing of pending writes > > > - is that intentional? It's not called out in the changelog and seems like > > > something that could cause issues if someone runs on a system where > > > the firmware does implement runtime suspend. > > > Runtime suspend is not enabled with ACPI firmware. Converted compiler flag in v1 to runtime check. > > We must add more changes like setting DPM flags for runtime pm support with ACPI. > > Can take this as part of a different series. > > It at least needs to be clearer what's going on here, the changelog > doesn't match the code and it's not obvious from the code that ACPI > won't kick in and power manage the device as things stand. Understood Mark. I will add comments to make it clear. Also update change log indicating runtime suspend does not work with ACPI.
