From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Hunter Subject: Re: [RFC v2 2/2] sdhci: Prevent SD from doing high-speed timing when broken-highspeed property is set Date: Mon, 17 Oct 2016 09:56:19 +0300 Message-ID: <58380ee1-15d0-9eb6-fe89-f1bb9ec24af2@intel.com> References: <1476297656-7019-1-git-send-email-zach.brown@ni.com> <1476297656-7019-3-git-send-email-zach.brown@ni.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: Received: from mga07.intel.com ([134.134.136.100]:29356 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750752AbcJQHBU (ORCPT ); Mon, 17 Oct 2016 03:01:20 -0400 In-Reply-To: <1476297656-7019-3-git-send-email-zach.brown@ni.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Zach Brown , ulf.hansson@linaro.org Cc: robh+dt@kernel.org, mark.rutland@arm.com, linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org On 12/10/16 21:40, Zach Brown wrote: > When the broken-highspeed property is set the sdhci driver will not > go into highspeed mode even if the controller and card appear to > otherwise support highspeed mode. > > This is useful in cases where the controller and card support highspeed, > but the board configuration or some other issue make highspeed > impossible. For example, we send the SDIO lines through a fpga so we > need the data to change on the falling edge of the clock or there will > be issues with hold time. > > Signed-off-by: Zach Brown Assuming the DT property is accepted: Acked-by: Adrian Hunter > --- > drivers/mmc/host/sdhci.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > index 4805566..17e6c50 100644 > --- a/drivers/mmc/host/sdhci.c > +++ b/drivers/mmc/host/sdhci.c > @@ -22,6 +22,7 @@ > #include > #include > #include > +#include > > #include > > @@ -3274,7 +3275,8 @@ int sdhci_setup_host(struct sdhci_host *host) > if (host->quirks2 & SDHCI_QUIRK2_HOST_NO_CMD23) > mmc->caps &= ~MMC_CAP_CMD23; > > - if (host->caps & SDHCI_CAN_DO_HISPD) > + if ((host->caps & SDHCI_CAN_DO_HISPD) && > + !(of_property_read_bool(mmc_dev(mmc)->of_node, "broken-highspeed"))) > mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED; > > if ((host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION) && >