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From: "Subhash Jadavani" <subhashj@codeaurora.org>
To: linux-mmc@vger.kernel.org, "'Nath,
	Arindam'" <Arindam.Nath@amd.com>,
	'Philip Rakity' <prakity@marvell.com>
Cc: linux-arm-msm@vger.kernel.org
Subject: RE: [PATCH v1 1/1] mmc: sd: UHS-I bus speed should be set last in UHS initialization
Date: Fri, 5 Aug 2011 21:55:09 +0530	[thread overview]
Message-ID: <000001cc538c$40e3a790$c2aaf6b0$@org> (raw)
In-Reply-To: <1312454295-10609-1-git-send-email-subhashj@codeaurora.org>

Chris, Arindam, Philip,

Please let me know you comments on this reworked patch.

Regards,
Subhash

> -----Original Message-----
> From: linux-arm-msm-owner@vger.kernel.org [mailto:linux-arm-msm-
> owner@vger.kernel.org] On Behalf Of Subhash Jadavani
> Sent: Thursday, August 04, 2011 4:08 PM
> To: linux-mmc@vger.kernel.org
> Cc: linux-arm-msm@vger.kernel.org; Subhash Jadavani
> Subject: [PATCH v1 1/1] mmc: sd: UHS-I bus speed should be set last in
> UHS initialization
> 
> mmc_sd_init_uhs_card function sets the driver type, current limit
> and bus speed mode on card as well as on host controller side.
> 
> Currently bus speed mode is set by sending CMD6 to card and
> immediately setting the timing mode in host controller. But
> then before initiating tuning sequence, it also tries to set
> current limit by sending CMD6 to card which results in data
> timeout errors in controller if bus speed mode is SDR50/SDR104 mode.
> 
> So basically bus speed mode should be set only after current limit
> is set in the card and immediately after setting the bus speed mode,
> tuning sequence should be initiated.
> 
> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
> ---
>  drivers/mmc/core/sd.c |   65 ++++++++++++++++++++++++++++++++++-------
> --------
>  1 files changed, 45 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
> index ff27741..769e587 100644
> --- a/drivers/mmc/core/sd.c
> +++ b/drivers/mmc/core/sd.c
> @@ -459,10 +459,9 @@ static int sd_select_driver_type(struct mmc_card
> *card, u8 *status)
>  	return 0;
>  }
> 
> -static int sd_set_bus_speed_mode(struct mmc_card *card, u8 *status)
> +static int sd_get_bus_speed_mode(struct mmc_card *card)
>  {
> -	unsigned int bus_speed = 0, timing = 0;
> -	int err;
> +	int bus_speed = 0;
> 
>  	/*
>  	 * If the host doesn't support any of the UHS-I modes, fallback
> on
> @@ -475,32 +474,57 @@ static int sd_set_bus_speed_mode(struct mmc_card
> *card, u8 *status)
>  	if ((card->host->caps & MMC_CAP_UHS_SDR104) &&
>  	    (card->sw_caps.sd3_bus_mode & SD_MODE_UHS_SDR104)) {
>  			bus_speed = UHS_SDR104_BUS_SPEED;
> -			timing = MMC_TIMING_UHS_SDR104;
> -			card->sw_caps.uhs_max_dtr = UHS_SDR104_MAX_DTR;
>  	} else if ((card->host->caps & MMC_CAP_UHS_DDR50) &&
>  		   (card->sw_caps.sd3_bus_mode & SD_MODE_UHS_DDR50)) {
>  			bus_speed = UHS_DDR50_BUS_SPEED;
> -			timing = MMC_TIMING_UHS_DDR50;
> -			card->sw_caps.uhs_max_dtr = UHS_DDR50_MAX_DTR;
>  	} else if ((card->host->caps & (MMC_CAP_UHS_SDR104 |
>  		    MMC_CAP_UHS_SDR50)) && (card->sw_caps.sd3_bus_mode &
>  		    SD_MODE_UHS_SDR50)) {
>  			bus_speed = UHS_SDR50_BUS_SPEED;
> -			timing = MMC_TIMING_UHS_SDR50;
> -			card->sw_caps.uhs_max_dtr = UHS_SDR50_MAX_DTR;
>  	} else if ((card->host->caps & (MMC_CAP_UHS_SDR104 |
>  		    MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR25)) &&
>  		   (card->sw_caps.sd3_bus_mode & SD_MODE_UHS_SDR25)) {
>  			bus_speed = UHS_SDR25_BUS_SPEED;
> -			timing = MMC_TIMING_UHS_SDR25;
> -			card->sw_caps.uhs_max_dtr = UHS_SDR25_MAX_DTR;
>  	} else if ((card->host->caps & (MMC_CAP_UHS_SDR104 |
>  		    MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR25 |
>  		    MMC_CAP_UHS_SDR12)) && (card->sw_caps.sd3_bus_mode &
>  		    SD_MODE_UHS_SDR12)) {
>  			bus_speed = UHS_SDR12_BUS_SPEED;
> -			timing = MMC_TIMING_UHS_SDR12;
> -			card->sw_caps.uhs_max_dtr = UHS_SDR12_MAX_DTR;
> +	}
> +
> +	return bus_speed;
> +}
> +
> +static int sd_set_bus_speed_mode(struct mmc_card *card, u8 *status)
> +{
> +	int err, bus_speed;
> +	unsigned int timing = 0;
> +
> +	bus_speed = sd_get_bus_speed_mode(card);
> +
> +	switch (bus_speed) {
> +	case UHS_SDR104_BUS_SPEED:
> +		timing = MMC_TIMING_UHS_SDR104;
> +		card->sw_caps.uhs_max_dtr = UHS_SDR104_MAX_DTR;
> +		break;
> +	case UHS_DDR50_BUS_SPEED:
> +		timing = MMC_TIMING_UHS_DDR50;
> +		card->sw_caps.uhs_max_dtr = UHS_DDR50_MAX_DTR;
> +		break;
> +	case UHS_SDR50_BUS_SPEED:
> +		timing = MMC_TIMING_UHS_SDR50;
> +		card->sw_caps.uhs_max_dtr = UHS_SDR50_MAX_DTR;
> +		break;
> +	case UHS_SDR25_BUS_SPEED:
> +		timing = MMC_TIMING_UHS_SDR25;
> +		card->sw_caps.uhs_max_dtr = UHS_SDR25_MAX_DTR;
> +		break;
> +	case UHS_SDR12_BUS_SPEED:
> +		timing = MMC_TIMING_UHS_SDR12;
> +		card->sw_caps.uhs_max_dtr = UHS_SDR12_MAX_DTR;
> +		break;
> +	default:
> +		return 0;
>  	}
> 
>  	card->sd_bus_speed = bus_speed;
> @@ -522,6 +546,7 @@ static int sd_set_bus_speed_mode(struct mmc_card
> *card, u8 *status)
>  static int sd_set_current_limit(struct mmc_card *card, u8 *status)
>  {
>  	int current_limit = 0;
> +	unsigned int bus_speed = sd_get_bus_speed_mode(card);
>  	int err;
> 
>  	/*
> @@ -529,9 +554,9 @@ static int sd_set_current_limit(struct mmc_card
> *card, u8 *status)
>  	 * bus speed modes. For other bus speed modes, we set the default
>  	 * current limit of 200mA.
>  	 */
> -	if ((card->sd_bus_speed == UHS_SDR50_BUS_SPEED) ||
> -	    (card->sd_bus_speed == UHS_SDR104_BUS_SPEED) ||
> -	    (card->sd_bus_speed == UHS_DDR50_BUS_SPEED)) {
> +	if ((bus_speed == UHS_SDR50_BUS_SPEED) ||
> +	    (bus_speed == UHS_SDR104_BUS_SPEED) ||
> +	    (bus_speed == UHS_DDR50_BUS_SPEED)) {
>  		if (card->host->caps & MMC_CAP_MAX_CURRENT_800) {
>  			if (card->sw_caps.sd3_curr_limit &
> SD_MAX_CURRENT_800)
>  				current_limit = SD_SET_CURRENT_LIMIT_800;
> @@ -613,13 +638,13 @@ static int mmc_sd_init_uhs_card(struct mmc_card
> *card)
>  	if (err)
>  		goto out;
> 
> -	/* Set bus speed mode of the card */
> -	err = sd_set_bus_speed_mode(card, status);
> +	/* Set current limit for the card */
> +	err = sd_set_current_limit(card, status);
>  	if (err)
>  		goto out;
> 
> -	/* Set current limit for the card */
> -	err = sd_set_current_limit(card, status);
> +	/* Set bus speed mode of the card */
> +	err = sd_set_bus_speed_mode(card, status);
>  	if (err)
>  		goto out;
> 
> --
> 1.7.1.1
> 
> --
> Sent by a consultant of the Qualcomm Innovation Center, Inc.
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
> Forum.
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-arm-
> msm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

  reply	other threads:[~2011-08-05 16:25 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-04 10:38 [PATCH v1 1/1] mmc: sd: UHS-I bus speed should be set last in UHS initialization Subhash Jadavani
2011-08-05 16:25 ` Subhash Jadavani [this message]
2011-08-05 17:23   ` Nath, Arindam
2011-08-08  6:39     ` Subhash Jadavani
2011-08-08  6:46       ` Nath, Arindam
2011-08-08 15:19         ` Philip Rakity

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