From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2813352F6F for ; Thu, 28 Mar 2024 13:25:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711632338; cv=none; b=Cce0eLEDK3qQJHve6G/IruicGpT2SH8X4VaiG7f7n+rtAQ7QZu515iLoyTBl0pqmdt/FdHTizghF2efTApQJbSPymFdNeh5HssHd5K6Y8WvZgbcdSjWCCCE/rG6BJ6/AAWs7wEvDJORt7UX/O1Oe+cALs4vzL7EPE04BeYF50Ec= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711632338; c=relaxed/simple; bh=VjZ0qzupPy28bMkRtM24lJPeXcSzB+GsGth6y5l4UmA=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=eYG303jOXIsxn+IJBpAsBK5/Tu28SUNPefMnVDMK9QwCqklWJN8goxUuPQt/tNeDsXa4FFoZvXSFUQwLjvTAfulbbHXdOqO6KZY/1EPYBBNfDtKlP4wORibdVva5yr6VHJLTY4MWJMZfbS5t9myq6JYbAPgw+PSHPvPyfszg8wg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B65D51476; Thu, 28 Mar 2024 06:26:07 -0700 (PDT) Received: from [10.1.35.17] (e133047.arm.com [10.1.35.17]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8B8AE3F64C; Thu, 28 Mar 2024 06:25:33 -0700 (PDT) Message-ID: <0cc46baf-8924-4ca7-98f3-c8376f7a5d87@arm.com> Date: Thu, 28 Mar 2024 13:25:31 +0000 Precedence: bulk X-Mailing-List: linux-mmc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: SD card specification and eSDHC controller To: Patryk , linux-mmc@vger.kernel.org References: Content-Language: en-US From: Christian Loehle In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 28/03/2024 13:13, Patryk wrote: > Hi, > I've got a question regarding sd cards, their specifications, and the > ability to support them by a host controller. > In my eSDHC (NXP LS1028a soc) features summary I can find the following: > - Conforms to the SD Host controller standard specification version > 3.0, including test event register support > - Compatible with the SD memory card specification version 3.01, and > supports the high-capacity SD memory card > - Compatible with the SDIO card specification version 3.0 > > I have found that SD cards compatible with SD card specification 4.10 > and higher support something like an extension register and in > particular power management. I've searched through kernel code and > found that these registers are parsed by the let's say generic part of > sd/mmc subsystem not by the host controller driver. > Does it mean that I can connect the SD card compatible with spec 4.10 > and expect that the sd/mmc subsystem will use power management > features if the card supports them? Yes. mmc core will handle it if the card supports it. "power management features" is a bit misleading, it's SD_EXT_POWER_OFF_NOTIFY. > Best regards > Patryk >