Re: [PATCH 05/12] mmc: sdhci-omap: Workaround for Errata i802

From: Adrian Hunter
Date: Thu Dec 21 2017 - 04:11:11 EST


On 14/12/17 15:09, Kishon Vijay Abraham I wrote:
> Errata i802 in AM572x Sitara Processors Silicon Revision 2.0, 1.1
> (SPRZ429K July 2014âRevised March 2017 [1]) mentions
> DCRC error interrupts (MMCHS_STAT[21] DCRC=0x1) can occur
> during the tuning procedure and it has to be disabled during the
> tuning procedure Implement workaround for Errata i802 here..
>
> [1] -> http://www.ti.com/lit/er/sprz429k/sprz429k.pdf
>
> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>

Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

> ---
> drivers/mmc/host/sdhci-omap.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
> index df8a0a472996..b20f4c79ccc6 100644
> --- a/drivers/mmc/host/sdhci-omap.c
> +++ b/drivers/mmc/host/sdhci-omap.c
> @@ -266,6 +266,7 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode)
> struct sdhci_pltfm_host *pltfm_host;
> struct sdhci_omap_host *omap_host;
> struct device *dev;
> + u32 ier = host->ier;
>
> pltfm_host = sdhci_priv(host);
> omap_host = sdhci_pltfm_priv(pltfm_host);
> @@ -283,6 +284,16 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode)
> reg |= DLL_SWT;
> sdhci_omap_writel(omap_host, SDHCI_OMAP_DLL, reg);
>
> + /*
> + * OMAP5/DRA74X/DRA72x Errata i802:
> + * DCRC error interrupts (MMCHS_STAT[21] DCRC=0x1) can occur
> + * during the tuning procedure. So disable it during the
> + * tuning procedure.
> + */
> + ier &= ~SDHCI_INT_DATA_CRC;
> + sdhci_writel(host, ier, SDHCI_INT_ENABLE);
> + sdhci_writel(host, ier, SDHCI_SIGNAL_ENABLE);
> +
> while (phase_delay <= MAX_PHASE_DELAY) {
> sdhci_omap_set_dll(omap_host, phase_delay);
>
> @@ -328,6 +339,8 @@ static int sdhci_omap_execute_tuning(struct mmc_host *mmc, u32 opcode)
>
> ret:
> sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
> + sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
> + sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
> return ret;
> }
>
>