RE: [PATCH 1/2] mmc: sdhci-esdhc-imx: fix the mask for tuning start point

From: Bough Chen <haibo.chen@nxp.com>
To: Kevin Groeneveld <kgroeneveld@lenbrook.com>,
	"adrian.hunter@intel.com" <adrian.hunter@intel.com>,
	"ulf.hansson@linaro.org" <ulf.hansson@linaro.org>,
	"linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>
Cc: dl-linux-imx <linux-imx@nxp.com>,
	"shawnguo@kernel.org" <shawnguo@kernel.org>,
	"s.hauer@pengutronix.de" <s.hauer@pengutronix.de>,
	"kernel@pengutronix.de" <kernel@pengutronix.de>,
	"festevam@gmail.com" <festevam@gmail.com>,
	Aisheng Dong <aisheng.dong@nxp.com>,
	"Y.B. Lu" <yangbo.lu@nxp.com>
Subject: RE: [PATCH 1/2] mmc: sdhci-esdhc-imx: fix the mask for tuning start point
Date: Fri, 2 Dec 2022 03:35:21 +0000	[thread overview]
Message-ID: <DB7PR04MB4010BBDABCFBDB5487292B9D90179@DB7PR04MB4010.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <4425d932-186c-1d14-e728-0c45d1bd8081@lenbrook.com>

> -----Original Message-----
> From: Kevin Groeneveld <kgroeneveld@lenbrook.com>
> Sent: 2022年12月2日 1:34
> To: Bough Chen <haibo.chen@nxp.com>; adrian.hunter@intel.com;
> ulf.hansson@linaro.org; linux-mmc@vger.kernel.org
> Cc: dl-linux-imx <linux-imx@nxp.com>; shawnguo@kernel.org;
> s.hauer@pengutronix.de; kernel@pengutronix.de; festevam@gmail.com;
> Aisheng Dong <aisheng.dong@nxp.com>; Y.B. Lu <yangbo.lu@nxp.com>
> Subject: Re: [PATCH 1/2] mmc: sdhci-esdhc-imx: fix the mask for tuning start
> point
> 
> On 2020-05-26 06:22, haibo.chen@nxp.com wrote:
> > According the RM, the bit[6~0] of register ESDHC_TUNING_CTRL is
> > TUNING_START_TAP, bit[7] of this register is to disable the command
> > CRC check for standard tuning. So fix it here.
> 
> Which RM? I just checked imx6sl, imx7s and imx8mm reference manuals and
> they all show bits 7~0 is for TUNING_START_TAP.

Please refer to the latest imx93 RM, I just confirm that this RM already correct this info.

> 
> I have been experiencing some infrequent hard to reproduce communication
> errors with an SDIO WiFi module on imx8mm and wondered if this could be
> related.

This should related to the auto tuning bit setting, usdhc has an IC bug of the auto tuning method for SDIO device which has a interrupt input.
Please refer to https://patchwork.kernel.org/project/linux-mmc/patch/1629285415-7495-4-git-send-email-haibo.chen@nxp.com/
I will continue to upstream this these weeks.

Best Regards
Haibo Chen
> 
> For example:
> ath10k_sdio mmc2:0001:1: failed to write to address 0x129ec: -84
> 
> 
> Kevin