From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guillaume Gardet Date: Thu, 26 Apr 2018 15:15:38 +0200 Subject: [U-Boot] [U-Boot, BUG] snow: mmc: SD card access broken: unable to select a mode In-Reply-To: <24e6d3e1-bf00-2020-7ea6-06be57aca005@samsung.com> References: <24e6d3e1-bf00-2020-7ea6-06be57aca005@samsung.com> Message-ID: <2e890fb7-a86f-cfde-e770-efa674768cda@free.fr> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: u-boot@lists.denx.de Le 26/04/2018 à 12:31, Jaehoon Chung a écrit : > Hi, > > On 04/09/2018 09:02 PM, Guillaume Gardet wrote: >> Hi Jaehoon, >> >> There are problems with SD card access on Samsung Chromebook (snow) with latest master (and also 2018.05-rc1 and 2018.03). >> >> eMMC is ok, but SD card access leads to 'unable to select a mode' problem. If I disable HS mode, I can access the SD card without problem: >> ******************************************************************************** >> ******************************************************************************** >> >> Once we try to select HS mode, all access to SD card result in failure, even when trying to setup a lower frequency mode, including SD legacy at 25 MHz. >> >> Any idea what is going? Maybe you have fixes pending? > Sorry for late. Hmm. I will check your issue. Just disable MMC_MODE_HS, then it's working fine? > or HS_52MHz? I tried to disable HS_52MHz only and it did not fix the problem. Then I tried to disable both HS and HS_52MHz and it fixed the problem. Guillaume > > Best Regards, > Jaehoon Chung > >> >> Guillaume >> >> diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c >> index 23f642980bf..28f4fa0f213 100644 >> --- a/drivers/mmc/dw_mmc.c >> +++ b/drivers/mmc/dw_mmc.c >> @@ -508,7 +508,8 @@ void dwmci_setup_cfg(struct mmc_config *cfg, struct dwmci_host *host, >>          cfg->host_caps |= MMC_MODE_4BIT; >>          cfg->host_caps &= ~MMC_MODE_8BIT; >>      } >> -    cfg->host_caps |= MMC_MODE_HS | MMC_MODE_HS_52MHz; >> +    /* Temp workaround for Chromebook snow to avoid the 'unable to select a mode' error */ >> +//     cfg->host_caps |= MMC_MODE_HS | MMC_MODE_HS_52MHz; >> >>      cfg->b_max = CONFIG_SYS_MMC_MAX_BLK_COUNT; >>  } >> >