From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Hunter Subject: Re: [PATCH V4 07/10] mmc: tegra: add Tegra186 WAR for CQE Date: Mon, 25 Mar 2019 12:41:32 +0200 Message-ID: References: <1553402727-23130-1-git-send-email-skomatineni@nvidia.com> <1553402727-23130-7-git-send-email-skomatineni@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1553402727-23130-7-git-send-email-skomatineni@nvidia.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Sowjanya Komatineni , ulf.hansson@linaro.org, robh+dt@kernel.org, mark.rutland@arm.com, riteshh@codeaurora.org Cc: thierry.reding@gmail.com, jonathanh@nvidia.com, anrao@nvidia.com, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org, devicetree@vger.kernel.org List-Id: linux-tegra@vger.kernel.org On 24/03/19 6:45 AM, Sowjanya Komatineni wrote: > Tegra186 CQHCI host has a known bug where CQHCI controller selects > DATA_PRESENT_SELECT bit to 1 for DCMDs with R1B response type and > since DCMD does not trigger any data transfer, DCMD task complete > happens leaving the DATA FSM of host controller in wait state for > the data. > > This effects the data transfer tasks issued after the DCMDs with > R1b response type resulting in timeout. > > SW WAR is to set CMD_TIMING to 1 in DCMD task descriptor. This bug > and SW WAR is applicable only for Tegra186 and not for Tegra194. > > This patch implements this WAR thru NVQUIRK_CQHCI_DCMD_R1B_CMD_TIMING > for Tegra186 and also implements update_dcmd_desc of cqhci_host_ops > interface to set CMD_TIMING bit depending on the NVQUIRK. > > Tested-by: Jon Hunter > Reviewed-by: Ritesh Harjani > Signed-off-by: Sowjanya Komatineni Acked-by: Adrian Hunter > --- > drivers/mmc/host/sdhci-tegra.c | 17 ++++++++++++++++- > 1 file changed, 16 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c > index f1aa0591112a..2f08b6e480df 100644 > --- a/drivers/mmc/host/sdhci-tegra.c > +++ b/drivers/mmc/host/sdhci-tegra.c > @@ -106,6 +106,7 @@ > #define NVQUIRK_HAS_PADCALIB BIT(6) > #define NVQUIRK_NEEDS_PAD_CONTROL BIT(7) > #define NVQUIRK_DIS_CARD_CLK_CONFIG_TAP BIT(8) > +#define NVQUIRK_CQHCI_DCMD_R1B_CMD_TIMING BIT(9) > > /* SDMMC CQE Base Address for Tegra Host Ver 4.1 and Higher */ > #define SDHCI_TEGRA_CQE_BASE_ADDR 0xF000 > @@ -1123,6 +1124,18 @@ static void tegra_sdhci_voltage_switch(struct sdhci_host *host) > tegra_host->pad_calib_required = true; > } > > +static void sdhci_tegra_update_dcmd_desc(struct mmc_host *mmc, > + struct mmc_request *mrq, u64 *data) > +{ > + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(mmc_priv(mmc)); > + struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host); > + const struct sdhci_tegra_soc_data *soc_data = tegra_host->soc_data; > + > + if (soc_data->nvquirks & NVQUIRK_CQHCI_DCMD_R1B_CMD_TIMING && > + mrq->cmd->flags & MMC_RSP_R1B) > + *data |= CQHCI_CMD_TIMING(1); > +} > + > static void sdhci_tegra_cqe_enable(struct mmc_host *mmc) > { > struct cqhci_host *cq_host = mmc->cqe_private; > @@ -1164,6 +1177,7 @@ static const struct cqhci_host_ops sdhci_tegra_cqhci_ops = { > .enable = sdhci_tegra_cqe_enable, > .disable = sdhci_cqe_disable, > .dumpregs = sdhci_tegra_dumpregs, > + .update_dcmd_desc = sdhci_tegra_update_dcmd_desc, > }; > > static const struct sdhci_ops tegra_sdhci_ops = { > @@ -1345,7 +1359,8 @@ static const struct sdhci_tegra_soc_data soc_data_tegra186 = { > NVQUIRK_HAS_PADCALIB | > NVQUIRK_DIS_CARD_CLK_CONFIG_TAP | > NVQUIRK_ENABLE_SDR50 | > - NVQUIRK_ENABLE_SDR104, > + NVQUIRK_ENABLE_SDR104 | > + NVQUIRK_CQHCI_DCMD_R1B_CMD_TIMING, > .min_tap_delay = 84, > .max_tap_delay = 136, > }; >