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From: Lars-Peter Clausen <lars@metafoo.de>
To: Daniel Baluta <daniel.baluta@gmail.com>
Cc: Mark Brown <broonie@kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: Using regmap_update_bits to update a write only register
Date: Fri, 06 Mar 2015 18:36:23 +0100	[thread overview]
Message-ID: <54F9E597.2050301@metafoo.de> (raw)
In-Reply-To: <CAEnQRZCb_S1ngMs+VQhMacKNVPf552qeaoPJ6YPydaHHOmRXzA@mail.gmail.com>

On 03/06/2015 06:26 PM, Daniel Baluta wrote:
[...]
> I can reproduce the problem with:
>
> static struct reg_default xxx_reg_defaults[] = {
>          { XXX_REG_CTRL0,  0x00 },
>          { XXX_REG_CTRL1,  0x00 },
>          { XXX_REG_STATUS, 0x00 },
> };
>
> but, not if the reg default definition is:
>
> static struct reg_default xxx_reg_defaults[] = {
>          { XXX_REG_STATUS, 0x00 },
>          { XXX_REG_CTRL0,  0x00 },
>          { XXX_REG_CTRL1,  0x00 },
>    };
>
> Is this normal?

That's a rhetorical question, right?

It might be that there is a bug when growing a rbblock to the left. It 
probably went unnoticed because everybody has their reg defaults ordered in 
ascending order.

Try to put a few debug printks into regcache_rbtree_write() and 
regcache_rbtree_insert_to_block() to see what exactly is going on when a new 
register is inserted into the block. How do base_reg and top_reg change.

- Lars

  reply	other threads:[~2015-03-06 17:36 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-05 17:35 Using regmap_update_bits to update a write only register Daniel Baluta
2015-03-05 17:53 ` Mark Brown
     [not found]   ` <CAEnQRZCb0k7_W1gt7qCTqbQqDwzJ_bJkDYS1FHthKTA8sP19Qg@mail.gmail.com>
2015-03-06 11:21     ` Mark Brown
2015-03-06 12:45       ` Lars-Peter Clausen
2015-03-06 13:27         ` Daniel Baluta
2015-03-06 17:26           ` Daniel Baluta
2015-03-06 17:36             ` Lars-Peter Clausen [this message]
2015-03-06 17:39               ` Lars-Peter Clausen
2015-03-06 19:48               ` Daniel Baluta
2015-03-07 11:06                 ` Mark Brown
2015-03-07 16:07                 ` Lars-Peter Clausen
2015-03-07 11:05           ` Mark Brown

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