From: Stefan Roese <sr@denx.de>
To: Simon Glass <sjg@chromium.org>
Cc: "Michael Walle" <michael@walle.cc>,
"U-Boot Mailing List" <u-boot@lists.denx.de>,
"Pali Rohár" <pali@kernel.org>, "Tony Dinh" <mibodhi@gmail.com>
Subject: Re: [PATCH 2/6] timer: orion-timer: Add timer_get_boot_us() for BOOTSTAGE support
Date: Thu, 1 Sep 2022 07:33:35 +0200 [thread overview]
Message-ID: <b9612ef3-509a-8156-8613-4921d2c00523@denx.de> (raw)
In-Reply-To: <CAPnjgZ1PqFOJrgpTiGyfLVFDCh95R-eq=ux4e8fxwusTC=4xEQ@mail.gmail.com>
Hi Simon,
On 31.08.22 19:44, Simon Glass wrote:
<snip>
>>> It is needed because bootstage is called before driver model is ready.
>>> In fact it can be used to time driver model things.
>>
>> I see, makes sense. This brings up my next questions though, why isn't
>> CONFIG_TIMER_EARLY enough in this case? AFAICT it's targeted exactly
>> for this early (pre DM) bootstage. From drivers/timer/Kconfig:
>>
>> config TIMER_EARLY
>> bool "Allow timer to be used early in U-Boot"
>> depends on TIMER
>> # initr_bootstage() requires a timer and is called before initr_dm()
>> # so only the early timer is available
>> default y if X86 && BOOTSTAGE
>> help
>> In some cases the timer must be accessible before driver model is
>> active. Examples include when using CONFIG_TRACE to trace U-Boot's
>> execution before driver model is set up. Enable this option to
>> use an early timer. These functions must be supported by your timer
>> driver: timer_early_get_count() and timer_early_get_rate().
>>
>> So again, do we really need timer_get_boot_us() or isn't it enough
>> to select TIMER_EARLY when BOOTSTAGE is enabled?
>
> The timer is for milliseconds but for bootstage we need microseconds.
>
> Perhaps the ultimate solution here is to support a microsecond timer
> through the TIMER api and use the TIMER_EARLY thing to provide
> timer_get_boot_us(), perhaps renaming to timer_early_get_us() ?
Yes, sounds like a plan. We should consolidate these implementations.
Let me think about it and perhaps do some basic implementations and
tests for a while.
Thanks,
Stefan
next prev parent reply other threads:[~2022-09-01 5:33 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-30 11:53 [PATCH 0/6] Enable CONFIG_TIMER for all Kirwood / MVEBU boards Stefan Roese
2022-08-30 11:53 ` [PATCH 1/6] timer: orion-timer: Add support for other Armada SoC's Stefan Roese
2022-08-30 11:53 ` [PATCH 2/6] timer: orion-timer: Add timer_get_boot_us() for BOOTSTAGE support Stefan Roese
2022-08-30 12:00 ` Michael Walle
2022-08-30 12:08 ` Stefan Roese
2022-08-30 15:56 ` Simon Glass
2022-08-31 5:57 ` Stefan Roese
2022-08-31 17:44 ` Simon Glass
2022-09-01 5:33 ` Stefan Roese [this message]
2022-08-30 11:53 ` [PATCH 3/6] arm: mvebu: Use CONFIG_TIMER on all MVEBU & KIRKWOOD platforms Stefan Roese
2022-08-30 12:04 ` Michael Walle
2022-08-30 12:11 ` Stefan Roese
2022-08-30 11:53 ` [PATCH 4/6] arm: mvebu: dts: Makefile: Compile Armada 375 dtb in a separate step Stefan Roese
2022-08-30 11:53 ` [PATCH 5/6] arm: mvebu: dts: armada-375.dtsi: Add timer0 & timer1 Stefan Roese
2022-08-30 11:53 ` [PATCH 6/6] arm: mvebu: dts: mvebu-u-boot.dtsi: Add "u-boot, dm-pre-reloc" to timer DT node Stefan Roese
2022-08-30 22:15 ` [PATCH 0/6] Enable CONFIG_TIMER for all Kirwood / MVEBU boards Tony Dinh
2022-08-31 5:02 ` Stefan Roese
2022-08-31 5:08 ` Stefan Roese
2022-08-31 6:12 ` Stefan Roese
2022-08-31 6:45 ` Tony Dinh
2022-08-31 6:30 ` Tony Dinh
2022-08-31 7:22 ` Stefan Roese
2022-08-31 15:08 ` Tony Dinh
2022-08-31 21:53 ` Tony Dinh
2022-09-01 1:38 ` Tony Dinh
2022-09-01 2:27 ` Simon Glass
2022-09-01 7:39 ` Tony Dinh
2022-09-01 9:27 ` Stefan Roese
2022-09-01 11:52 ` Stefan Herbrechtsmeier
2022-09-02 5:38 ` Stefan Roese
2022-09-01 14:34 ` Simon Glass
2022-09-01 23:46 ` Tony Dinh
2022-09-02 2:51 ` Tony Dinh
2022-09-02 3:49 ` Tony Dinh
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