From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alim Akhtar Subject: Re: mmc: dwmmc: exynos: Warn if HS400 is being used on non-Exynos5420 chipset Date: Fri, 15 Jul 2016 09:45:59 +0530 Message-ID: <5788637F.2070908@samsung.com> References: <1468502547-18571-1-git-send-email-k.kozlowski@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <1468502547-18571-1-git-send-email-k.kozlowski@samsung.com> Sender: linux-samsung-soc-owner@vger.kernel.org To: Krzysztof Kozlowski , Jaehoon Chung , Ulf Hansson , Kukjin Kim , linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Bartlomiej Zolnierkiewicz List-Id: linux-mmc@vger.kernel.org Hi Krzysztof, On 07/14/2016 06:52 PM, Krzysztof Kozlowski wrote: > Chipsets before Exynos5420 did not support HS400 so if MMC core tries to > configure HS400 timing, this might or might not work. Warn in such > cases because this is DTB misconfiguration. > > Signed-off-by: Krzysztof Kozlowski > --- Reviewed-by: Alim Akhtar > drivers/mmc/host/dw_mmc-exynos.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/dw_mmc-exynos.c b/drivers/mmc/host/dw_mmc-exynos.c > index da0ef1765735..7ab3d749b5ae 100644 > --- a/drivers/mmc/host/dw_mmc-exynos.c > +++ b/drivers/mmc/host/dw_mmc-exynos.c > @@ -225,8 +225,12 @@ static void dw_mci_exynos_config_hs400(struct dw_mci *host, u32 timing) > * Not supported to configure register > * related to HS400 > */ > - if (priv->ctrl_type < DW_MCI_TYPE_EXYNOS5420) > + if (priv->ctrl_type < DW_MCI_TYPE_EXYNOS5420) { > + if (timing == MMC_TIMING_MMC_HS400) > + dev_warn(host->dev, > + "cannot configure HS400, unsupported chipset\n"); > return; > + } > It is good to have extra bit of debug information handy. > dqs = priv->saved_dqs_en; > strobe = priv->saved_strobe_ctrl; >