Re: [PATCH V2 1/2] mmc: sdhci: Introduce max_timeout_count variable in sdhci_host

From: Adrian Hunter
Date: Tue Aug 03 2021 - 04:22:59 EST


On 29/07/21 7:46 am, Sarthak Garg wrote:
> Introduce max_timeout_count variable in the sdhci_host structure
> and use in timeout calculation. By default its set to 0xE
> (max timeout register value as per SDHC spec). But at the same time
> vendors drivers can update it if they support different max timeout
> register value than 0xE.

Looks fine. A couple of minor comments below.

>
> Signed-off-by: Sarthak Garg <sartgarg@xxxxxxxxxxxxxx>
> ---
> drivers/mmc/host/sdhci.c | 15 +++++++++------
> drivers/mmc/host/sdhci.h | 1 +
> 2 files changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index aba6e10..2debda3 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -939,16 +939,16 @@ static u8 sdhci_calc_timeout(struct sdhci_host *host, struct mmc_command *cmd,
> * timeout value.
> */
> if (host->quirks & SDHCI_QUIRK_BROKEN_TIMEOUT_VAL)
> - return 0xE;
> + return host->max_timeout_count;

Please adjust the comment above this that also refers to 0xE
e.g. "skip the check and use 0xE" -> "skip the check and use the maximum"

>
> /* Unspecified command, asume max */
> if (cmd == NULL)
> - return 0xE;
> + return host->max_timeout_count;
>
> data = cmd->data;
> /* Unspecified timeout, assume max */
> if (!data && !cmd->busy_timeout)
> - return 0xE;
> + return host->max_timeout_count;
>
> /* timeout in us */
> target_timeout = sdhci_target_timeout(host, cmd, data);
> @@ -968,15 +968,15 @@ static u8 sdhci_calc_timeout(struct sdhci_host *host, struct mmc_command *cmd,
> while (current_timeout < target_timeout) {
> count++;
> current_timeout <<= 1;
> - if (count >= 0xF)
> + if (count > host->max_timeout_count)
> break;
> }
>
> - if (count >= 0xF) {
> + if (count > host->max_timeout_count) {
> if (!(host->quirks2 & SDHCI_QUIRK2_DISABLE_HW_TIMEOUT))
> DBG("Too large timeout 0x%x requested for CMD%d!\n",
> count, cmd->opcode);
> - count = 0xE;
> + count = host->max_timeout_count;
> } else {
> *too_big = false;
> }
> @@ -3940,6 +3940,9 @@ struct sdhci_host *sdhci_alloc_host(struct device *dev,
> */
> host->adma_table_cnt = SDHCI_MAX_SEGS * 2 + 1;
>
> + if (!host->max_timeout_count)

'host' has just been (zero) allocated as part of 'mmc', so the 'if' is redundant here.

> + host->max_timeout_count = 0xE;
> +
> return host;
> }
>
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 074dc18..e8d04e4 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -517,6 +517,7 @@ struct sdhci_host {
>
> unsigned int max_clk; /* Max possible freq (MHz) */
> unsigned int timeout_clk; /* Timeout freq (KHz) */
> + u8 max_timeout_count; /* Vendor specific max timeout count */
> unsigned int clk_mul; /* Clock Muliplier value */
>
> unsigned int clock; /* Current clock (MHz) */
>