> -----Original Message----- > From: Andrew Jeffery <[email protected]> > Sent: Monday, January 25, 2021 8:47 AM > To: Ryan Chen <[email protected]>; Samuel Holland > <[email protected]>; Stephen Boyd <[email protected]>; Joel Stanley > <[email protected]> > Cc: BMC-SW <[email protected]>; linux-aspeed > <[email protected]>; Michael Turquette > <[email protected]>; Linux Kernel Mailing List > <[email protected]>; [email protected]; Linux ARM > <[email protected]> > Subject: Re: [PATCH 1/1] clk: aspeed: modify some default clks are critical > > > > On Fri, 22 Jan 2021, at 18:45, Ryan Chen wrote: > > Hello, > > How about this patch progress? > > It does impact a lot of machine that when BMC boot at u-boot. > > SUART is work for Host. But after boot into kernel, due to the clk > > disabled. > > The SUART is not work for Host anymore. > > Maybe it's worth taking Ryan's patch for now, and when the protected-clocks > binding gets merged we can rip out the CLK_IS_CRITICAL flags and convert the > Aspeed devicetrees to use protected-clocks instead? > > The only issue I see with that plan is it becomes ambiguous as to which clock > each platform considers crititical/in-need-of-protection. > Hello Joel, Will you take this patch? Or you have another approach I may modify for it.
Regards, Ryan > > > -----Original Message----- > > > From: Samuel Holland <[email protected]> > > > Sent: Thursday, October 29, 2020 10:25 AM > > > To: Stephen Boyd <[email protected]>; Joel Stanley <[email protected]> > > > Cc: Andrew Jeffery <[email protected]>; Michael Turquette > > > <[email protected]>; Ryan Chen <[email protected]>; > > > BMC-SW <[email protected]>; Linux ARM > > > <[email protected]>; linux-aspeed > > > <[email protected]>; [email protected]; Linux > > > Kernel Mailing List <[email protected]> > > > Subject: Re: Re: [PATCH 1/1] clk: aspeed: modify some default clks > > > are critical > > > > > > Stephen, > > > > > > On 10/14/20 12:16 PM, Stephen Boyd wrote: > > > > Quoting Joel Stanley (2020-10-13 22:28:00) > > > >> On Wed, 14 Oct 2020 at 02:50, Stephen Boyd <[email protected]> > wrote: > > > >>> > > > >>> Quoting Ryan Chen (2020-09-28 00:01:08) > > > >>>> In ASPEED SoC LCLK is LPC clock for all SuperIO device, > > > >>>> UART1/UART2 are default for Host SuperIO UART device, eSPI clk > > > >>>> for Host eSPI bus access eSPI slave channel, those clks can't > > > >>>> be disable should keep default, otherwise will affect Host side > > > >>>> access SuperIO and SPI slave > > > device. > > > >>>> > > > >>>> Signed-off-by: Ryan Chen <[email protected]> > > > >>>> --- > > > >>> > > > >>> Is there resolution on this thread? > > > >> > > > >> Not yet. > > > >> > > > >> We have a system where the BMC (management controller) controls > > > >> some clocks, but the peripherals that it's clocking are outside > > > >> the BMC's control. In this case, the host processor us using some > > > >> UARTs and what not independent of any code running on the BMC. > > > >> > > > >> Ryan wants to have them marked as critical so the BMC never > > > >> powers them > > > down. > > > >> > > > >> However, there are systems that don't use this part of the soc, > > > >> so for those implementations they are not critical and Linux on > > > >> the BMC can turn them off. > > > >> > > > >> Do you have any thoughts? Has anyone solved a similar problem > already? > > > >> > > > > > > > > Is this critical clocks in DT? Where we want to have different DT > > > > for different device configurations to indicate that some clks > > > > should be marked critical so they're never turned off and other > > > > times they aren't so they're turned off? > > > > > > > > It also sounds sort of like the protected-clocks binding. Where > > > > you don't want to touch certain clks depending on the usage > > > > configuration of the SoC. There is a patch to make that generic > > > > that I haven't applied because it looks wrong at first glance[1]. > > > > Maybe not registering those clks to the framework on the > > > > configuration that Ryan has is > > > good enough? > > > > > > Could you please be more specific than the patch "looks wrong"? I'm > > > more than happy to update the patch to address your concerns, but I > > > cannot do that unless I know what your concerns are. > > > > > > Regards, > > > Samuel > > > > > > > [1] > > > > https://lore.kernel.org/r/[email protected] > > > > g > > _______________________________________________ > > linux-arm-kernel mailing list > > [email protected] > > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > >
