From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-x22f.google.com (mail-qk0-x22f.google.com [IPv6:2607:f8b0:400d:c09::22f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 0970221B02B88 for ; Thu, 29 Jun 2017 07:27:38 -0700 (PDT) Received: by mail-qk0-x22f.google.com with SMTP id r62so77594230qkf.0 for ; Thu, 29 Jun 2017 07:29:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=71lDYnmAgmzFkat28jZrPHvWr12Ve+nIY9/mL950y88=; b=KS5oslUGw1dX9T9VPNDehMaS4VpLRY8/QySt9RS09KrDhLuusGm9FW4KVrQ5Y85pys aIYjVyBADmoo5KrGAE6HkzqEum9OqfB/KCWqCQ7uBZAYfvTTzJySSlCvfLlplUdatyq4 gjW/DKV2jLjxCiMQyMV9DzXlZS0UYUxVF3HyA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=71lDYnmAgmzFkat28jZrPHvWr12Ve+nIY9/mL950y88=; b=gYBb6ug+2gPlKyPBqhvaVB2e13bgqBFUCaZSE5oI9ii3bo7+O2cl5h7B7a0V93cvbh mW1a1rXl41Qc2XSNLMFWYlhRyL4CkarQbTQ7wOnFDnSHhqQez7WavWrz98+P9CMYUqQc mOCmszLAoHtUwOvk6QwAC7jcJcHiIT/mNIoi3fLlveZAlEuaTzLMDgy4FQMx7LPK3Lbx /IZeOXCrWCEsvH7AhaEpC4NrnreInZUvBJXttPwONf2rIxeSwTaedG2/AnhvoOZgY7Cq RrULXthnChV6CBz9DZugZZ5xPJDh/Y4VJvBjbZcow8ETHF/1MoH0WmfEcfsAMvjaGsIc +sCw== X-Gm-Message-State: AKS2vOwnQZtBR+kL4CnCmBwllrEi/sKckmpXmAECe8KMCRCmnUJItPMG o3tm3QZzqKzcRRoyGyVt67yYkMCT5DCw X-Received: by 10.55.79.198 with SMTP id d189mr18296628qkb.37.1498746549751; Thu, 29 Jun 2017 07:29:09 -0700 (PDT) MIME-Version: 1.0 Received: by 10.55.110.66 with HTTP; Thu, 29 Jun 2017 07:29:08 -0700 (PDT) In-Reply-To: <20170629120935.GS26676@bivouac.eciton.net> References: <1498726925-25860-1-git-send-email-jun.nie@linaro.org> <20170629120935.GS26676@bivouac.eciton.net> From: Jun Nie Date: Thu, 29 Jun 2017 22:29:08 +0800 Message-ID: To: Leif Lindholm Cc: Ard Biesheuvel , Haojian Zhuang , edk2-devel@lists.01.org, Shawn Guo , Jason Liu Subject: Re: [PATCH] EmbeddedPkg/MmcDxe: Correct argument of ECSD read X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Jun 2017 14:27:38 -0000 Content-Type: text/plain; charset="UTF-8" 2017-06-29 20:09 GMT+08:00 Leif Lindholm : > On Thu, Jun 29, 2017 at 05:02:05PM +0800, Jun Nie wrote: >> The argument of CMD8 should be stuff bits according to standard >> JESD84-A44. > > OK, I realise that "stuff bits" is a term used by the spec, so that is > probably sufficient explanation even though the term was known to me. > And the MdeModulePkg driver seems to agree on the technical point. > My question is why zeroes is the correct "stuff bits" value? Yes, it is defined in page 2 in spec. I guess 0 is best filling value than other value when we do not need a real value. stuff bit: filling 0 bits to ensure fixed length frames for commands and responses. > >> Contributed-under: TianoCore Contribution Agreement 1.0 >> Signed-off-by: Jun Nie >> --- >> EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c b/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c >> index 4ce0ddd..c28207e 100644 >> --- a/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c >> +++ b/EmbeddedPkg/Universal/MmcDxe/MmcIdentification.c >> @@ -210,7 +210,7 @@ EmmcIdentificationMode ( >> } >> >> // Fetch ECSD >> - Status = Host->SendCommand (Host, MMC_CMD8, RCA); >> + Status = Host->SendCommand (Host, MMC_CMD8, 0); >> if (EFI_ERROR (Status)) { >> DEBUG ((EFI_D_ERROR, "EmmcIdentificationMode(): ECSD fetch error, Status=%r.\n", Status)); >> } >> -- >> 1.9.1 >>