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Date: Tue, 30 Apr 2024 03:17:49 +0200
From: Dragan Simic <dsimic@manjaro.org>
To: Ulf Hansson <ulf.hansson@linaro.org>
Cc: linux-mmc@vger.kernel.org, Adrian Hunter <adrian.hunter@intel.com>, Avri
 Altman <avri.altman@wdc.com>, Felix Qin <xiaokeqinhealth@126.com>,
 linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mmc: core: Convert to use __mmc_poll_for_busy()
 SD_APP_OP_COND too
In-Reply-To: <20240425133034.79599-1-ulf.hansson@linaro.org>
References: <20240425133034.79599-1-ulf.hansson@linaro.org>
Message-ID: <581352225de29859544b88f95ae5de89@manjaro.org>
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Hello Ulf,

Please see my comment below.

On 2024-04-25 15:30, Ulf Hansson wrote:
> Similar to what has already been changed for eMMC and the 
> MMC_SEND_OP_COND
> (CMD1), let's convert the SD_APP_OP_COND (ACMD41) for SD cards to use 
> the
> common __mmc_poll_for_busy() too.
> 
> This change means the initial delay period, that starts as 10ms will 
> now
> increase for every loop when being busy. The total accepted timeout for
> being busy is 1s, which is according to the SD spec.
> 
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>  drivers/mmc/core/sd_ops.c | 77 +++++++++++++++++++++++++--------------
>  1 file changed, 50 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/mmc/core/sd_ops.c b/drivers/mmc/core/sd_ops.c
> index a59cd592f06e..3ce1ff336826 100644
> --- a/drivers/mmc/core/sd_ops.c
> +++ b/drivers/mmc/core/sd_ops.c
> @@ -19,6 +19,15 @@
>  #include "sd_ops.h"
>  #include "mmc_ops.h"
> 
> +#define SD_APP_OP_COND_PERIOD_US	(10 * 1000) /* 10ms */
> +#define SD_APP_OP_COND_TIMEOUT_MS	1000 /* 1s */
> +
> +struct sd_app_op_cond_busy_data {
> +	struct mmc_host *host;
> +	u32 ocr;
> +	struct mmc_command *cmd;
> +};
> +
>  int mmc_app_cmd(struct mmc_host *host, struct mmc_card *card)
>  {
>  	int err;
> @@ -115,10 +124,44 @@ int mmc_app_set_bus_width(struct mmc_card *card,
> int width)
>  	return mmc_wait_for_app_cmd(card->host, card, &cmd);
>  }
> 
> +static int sd_app_op_cond_cb(void *cb_data, bool *busy)
> +{
> +	struct sd_app_op_cond_busy_data *data = cb_data;
> +	struct mmc_host *host = data->host;
> +	struct mmc_command *cmd = data->cmd;
> +	u32 ocr = data->ocr;
> +	int err;

Minor nitpick...  An empty line should be added here, to
separate the variable definitions from the subsequent code.

Otherwise, the patch is looking to me, so please include my

Reviewed-by: Dragan Simic <dsimic@manjaro.org>

> +	*busy = false;
> +
> +	err = mmc_wait_for_app_cmd(host, NULL, cmd);
> +	if (err)
> +		return err;
> +
> +	/* If we're just probing, do a single pass. */
> +	if (ocr == 0)
> +		return 0;
> +
> +	/* Wait until reset completes. */
> +	if (mmc_host_is_spi(host)) {
> +		if (!(cmd->resp[0] & R1_SPI_IDLE))
> +			return 0;
> +	} else if (cmd->resp[0] & MMC_CARD_BUSY) {
> +		return 0;
> +	}
> +
> +	*busy = true;
> +	return 0;
> +}
> +
>  int mmc_send_app_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
>  {
>  	struct mmc_command cmd = {};
> -	int i, err = 0;
> +	struct sd_app_op_cond_busy_data cb_data = {
> +		.host = host,
> +		.ocr = ocr,
> +		.cmd = &cmd
> +	};
> +	int err;
> 
>  	cmd.opcode = SD_APP_OP_COND;
>  	if (mmc_host_is_spi(host))
> @@ -127,36 +170,16 @@ int mmc_send_app_op_cond(struct mmc_host *host,
> u32 ocr, u32 *rocr)
>  		cmd.arg = ocr;
>  	cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R3 | MMC_CMD_BCR;
> 
> -	for (i = 100; i; i--) {
> -		err = mmc_wait_for_app_cmd(host, NULL, &cmd);
> -		if (err)
> -			break;
> -
> -		/* if we're just probing, do a single pass */
> -		if (ocr == 0)
> -			break;
> -
> -		/* otherwise wait until reset completes */
> -		if (mmc_host_is_spi(host)) {
> -			if (!(cmd.resp[0] & R1_SPI_IDLE))
> -				break;
> -		} else {
> -			if (cmd.resp[0] & MMC_CARD_BUSY)
> -				break;
> -		}
> -
> -		err = -ETIMEDOUT;
> -
> -		mmc_delay(10);
> -	}
> -
> -	if (!i)
> -		pr_err("%s: card never left busy state\n", mmc_hostname(host));
> +	err = __mmc_poll_for_busy(host, SD_APP_OP_COND_PERIOD_US,
> +				  SD_APP_OP_COND_TIMEOUT_MS, &sd_app_op_cond_cb,
> +				  &cb_data);
> +	if (err)
> +		return err;
> 
>  	if (rocr && !mmc_host_is_spi(host))
>  		*rocr = cmd.resp[0];
> 
> -	return err;
> +	return 0;
>  }
> 
>  static int __mmc_send_if_cond(struct mmc_host *host, u32 ocr, u8 
> pcie_bits,