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From: Tony Lindgren <tony@atomide.com>
To: Julien Panis <jpanis@baylibre.com>
Cc: linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org,
	vigneshr@ti.com
Subject: Re: [PATCH] bus: ti-sysc: Use fsleep() instead of usleep_range() in sysc_reset()
Date: Wed, 13 Sep 2023 11:27:11 +0300	[thread overview]
Message-ID: <20230913082711.GH5285@atomide.com> (raw)
In-Reply-To: <20230822092744.GT11676@atomide.com>

* Tony Lindgren <tony@atomide.com> [230822 09:27]:
> * Julien Panis <jpanis@baylibre.com> [230821 14:24]:
> > The am335x-evm started producing boot errors because of subtle timing
> > changes:
> > 
> > Unhandled fault: external abort on non-linefetch (0x1008) at 0xf03c1010
> > ...
> > sysc_reset from sysc_probe+0xf60/0x1514
> > sysc_probe from platform_probe+0x5c/0xbc
> > ...
> > 
> > The fix consists in using the appropriate sleep function in sysc reset.
> > For flexible sleeping, fsleep is recommended. Here, sysc delay parameter
> > can take any value in [0 - 255] us range. As a result, fsleep() should
> > be used, calling udelay() for a sysc delay lower than 10 us.
> > 
> > Signed-off-by: Julien Panis <jpanis@baylibre.com>
> > Fixes: e709ed70d122 ("bus: ti-sysc: Fix missing reset delay handling")
> > ---
> > Fix boot errors for am335x-evm in sysc_reset(), by using fsleep() instead
> > of usleep_range() function. Thus, udelay() will be called if the configured
> > sysc delay is lower than 10 us (which is usually the case, since the value
> > set in the device tree is currently 2 us).
> 
> OK, interesting. Yeah I've only ever seen values of 2 us needed here.

Applied into fixes thanks

Tony

      reply	other threads:[~2023-09-13  8:27 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-21 14:24 [PATCH] bus: ti-sysc: Use fsleep() instead of usleep_range() in sysc_reset() Julien Panis
2023-08-22  9:27 ` Tony Lindgren
2023-09-13  8:27   ` Tony Lindgren [this message]

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