Re: [PATCH v10 1/5] drm/layerscape: Add Freescale DCU DRM driver

From: Alexander Stein <alexander.stein@systec-electronic.com>
To: Jianwei Wang <jianwei.wang@freescale.com>
Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
	airlied@linux.ie, daniel.vetter@ffwll.ch,
	mark.yao@rock-chips.com, scottwood@freescale.com,
	thierry.reding@gmail.com,
	Jianwei Wang <jianwei.wang.chn@gmail.com>,
	Alison Wang <b18965@freescale.com>,
	Xiubo Li <lixiubo@cmss.chinamobile.com>
Subject: Re: [PATCH v10 1/5] drm/layerscape: Add Freescale DCU DRM driver
Date: Mon, 20 Jul 2015 09:18:16 +0200	[thread overview]
Message-ID: <2160582.6fH0nmeH2v@ws-stein> (raw)
In-Reply-To: <1437129543-8037-1-git-send-email-jianwei.wang@freescale.com>

On Friday 17 July 2015 18:38:59, Jianwei Wang wrote:
> [...]
> +static const struct regmap_config fsl_dcu_regmap_config = {
> +	.reg_bits = 32,
> +	.reg_stride = 4,
> +	.val_bits = 32,
> +};

This defaults to REGCACHE_NONE which in the end sets regmap.cache_only = true.

> [...]
> +#ifdef CONFIG_PM_SLEEP
> +static int fsl_dcu_drm_pm_suspend(struct device *dev)
> +{
> +	struct fsl_dcu_drm_device *fsl_dev = dev_get_drvdata(dev);
> +
> +	if (!fsl_dev)
> +		return 0;
> +
> +	drm_kms_helper_poll_disable(fsl_dev->drm);
> +	regcache_cache_only(fsl_dev->regmap, true);

This should raise a warning (see http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/base/regmap/regcache.c#n472) as map->cache_bypass is set because of REGCACHE_NONE.
I think you set the cache_type to REGCACHE_FLAT, but neither _LZO or _RBTREE (see https://lkml.org/lkml/2015/7/16/552 for that)

Best regards,
Alexander
-- 
Dipl.-Inf. Alexander Stein
SYS TEC electronic GmbH
alexander.stein@systec-electronic.com

Legal and Commercial Address:
Am Windrad 2
08468 Heinsdorfergrund
Germany

Office: +49 (0) 3765 38600-11xx
Fax:    +49 (0) 0) 3765 38600-41xx

Managing Directors:
	Director Technology/CEO: Dipl.-Phys. Siegmar Schmidt;
	Director Commercial Affairs/COO: Dipl. Ing. (FH) Armin von Collrepp
Commercial Registry:
	Amtsgericht Chemnitz, HRB 28082; USt.-Id Nr. DE150534010