From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 170CB2D373E for ; Wed, 3 Sep 2025 19:00:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756926012; cv=none; b=jMtmWF9AFcSUzr/GoTPftLuxxCcFobqh0wnIrxeVNmEXcfqQqnORI7eicGQZZEPMYQjzXlk0uRBTRSd9cAUmAT8JZ4bKy8gxjxHylIDVIff5LQo8UdW/Rr+sImWVrmOvCE4u6dJ1y3WbKmWvf9DLm/ykgTRrJ/7bcZq8u+4hliE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756926012; c=relaxed/simple; bh=7genJ6xMU2Tnz7znyg25faH4YIFlvpZ5SHRBX9/NKTY=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=IZ3qCk3NBoAg2KbAJvk7ps6SsRzs+8yEpD8xXoHSsr/dop2pljZH9eTnXFncmhEPWVovyveW+mh7in7uJ1GwR+JvBHbMIex7VcJpse+O2h/f3KnNleQ5VZ9kkMAW35IbDVM/TAkImZzveRzSzF+yfe+1flkU34FGg8gZTz4IfuA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=k6RtkASq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="k6RtkASq" Received: by smtp.kernel.org (Postfix) with ESMTPS id 3DE42C4CEE7 for ; Wed, 3 Sep 2025 19:00:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756926011; bh=7genJ6xMU2Tnz7znyg25faH4YIFlvpZ5SHRBX9/NKTY=; h=From:To:Subject:Date:In-Reply-To:References:From; b=k6RtkASq27+wqpMhgQ15A+ZgQ8l1bDAJ7El1sl8+xfIlFg1Pt7dHlyFqB5Bqtt5lH AFuyFI+FrVlEG6BBBhrX6aCqsc1eEO/nJ2pB1OA8f89kaQjNke7tqajoQZeO5ApsnG SVNt5KrxUR1coVBJoAqSTpkQIBIpQYGCWx+/6WYPJT2NXBRQJZ6WCCENinm4CFUItY W+20wSMVvIIgYCWHaOMLSqmuQ1wOI8rs4DQXX7Qf7z62pYT1/Dx0zeL59fMEi79c0S ORdYqnZTK6aQHDuIvZRsKy9a5GeDPBvhorn55H4rTFmZ1fFx8aYUylZ5SmbQnuEzGH ojQbj7JhFHC9g== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id 3161BC4160E; Wed, 3 Sep 2025 19:00:11 +0000 (UTC) From: bugzilla-daemon@kernel.org To: linux-usb@vger.kernel.org Subject: [Bug 220491] usb_storage connected SD card disconnects/reconnects on resume from suspend Date: Wed, 03 Sep 2025 19:00:10 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: AssignedTo drivers_usb@kernel-bugs.kernel.org X-Bugzilla-Product: Drivers X-Bugzilla-Component: USB X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: paula@alumni.cse.ucsc.edu X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: drivers_usb@kernel-bugs.kernel.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 https://bugzilla.kernel.org/show_bug.cgi?id=3D220491 --- Comment #29 from Paul Ausbeck (paula@alumni.cse.ucsc.edu) --- I think it somewhat important to say why I reported the Samsung problem initially when I think that the emb-qm77 board may be a better canonical example. The emb-qm77 board appears canonical to me only in that the proble= m is reliably repeatable. The Samsung laptop is actually canonical in the relati= ve worth of a kernel fix. The emb-qm77 machine has 5 SATA ports, so I would not dream of actually using its USB 3.0 ports for mounting storage devices that need to survive suspend/resume. On the other hand, the Samsung laptop has only one m.2 SATA slot and one SD card slot. Right now, the ativ9 contains its original Samsung 256GB m.2 SATA drive and a Samsung 512GB U1/A2 SD card. I use the SD card for larger/downloaded files: video, images, audio, pdfs, downloaded web pages, compressed tarballs, and the m.2 SATA drive for everything else. The ativ9 = SD card reader limits the SD card to ~20MB/s, rather less than its 100MB/s U1 rating. Even at 20MB/s the USB 3.0 connection can theoretically support 40K 512B transactions per second. This is more than the few thousand specified = for the SD card's A2 rating. Knowing USB, though, the number of transactions actually available may likely be substantially less than 40k/s. Still, in my experience, USB 3.0 can support a few thousand transactions/s. I really like these Samsung U1/A2 cards. Even in a compromised reader like = in the ativ9, it is very possible to build a linux kernel on the SD card. The linux kernel build is so CPU limited that it barely notices that it's on an= SD card. These U1/A2 cards generally behave quite similarly to mmc connected soldered flash as in typical phone. I also trust these cards degrade proper= ly in that write problems start surfacing while it is still possible to recover previously written data from the card. I don't want to imply that write problems surface that often because they don't. Again, I really like these Samsung U1/A2 cards. I really like the Samsung ativ9 laptop as well. I paid $500 for it ten years ago. It is small, light and physically robust. It has a lot of bright displ= ay pixels. It is efficient and thus far the battery works as if new. It has an Atheros QCA6174 radio which actually does 2x2 MIMO. The wifi throughput can= be 25MB/s on a 40MHz 2.4GHz connection, and 50MB/s on a 80MHz 5GHz connection.= The QCA6174 firmware crashes on most suspend/resume cycles but the system recov= ers without any user intervention. I would not trade the known limitations of t= he ativ9 for any newer system with unknown limitations. --=20 You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.=