From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qv1-f45.google.com (mail-qv1-f45.google.com [209.85.219.45]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EF32D2F0664 for ; Tue, 12 Aug 2025 20:06:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.45 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755029201; cv=none; b=sNLuIuZ9UVSC8/CafjJPTses2MCY2lgwxvQwqjQL3vE2lG/KMkzEHvPvtjeiIR3LEejQt1lrNvdSLVhqjuqTDENEyf36XHwVE+PEZbNDx7q4fLN6oTyOCAjd9Ps1kZDJTdBiMtm0UDCMWOhVTkNHw2gmi/dD5ROwU5mXWHKcMt0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755029201; c=relaxed/simple; bh=i8HY5u63XJP2plaosaDKuXc1itBLuDy+0U6FlcOWZ20=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qrZTeuFt94wZlhMNIL300nvlmcgxQE/b4QDgdB2lEhJRgnj7/UVhrZjvA5g8xUmAOBWIlOTAi8cHOj0fWULc5FChAsMWTlFXd+bUgX0SDs2d13qPwgKtP9E0qUxRk2wXbug16RD0t7Da46JoW9U2LQ3ahRuHQZM/ok/KBgAd7F0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=rowland.harvard.edu; spf=fail smtp.mailfrom=g.harvard.edu; dkim=pass (2048-bit key) header.d=rowland.harvard.edu header.i=@rowland.harvard.edu header.b=ONN9quwT; arc=none smtp.client-ip=209.85.219.45 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=rowland.harvard.edu Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=g.harvard.edu Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rowland.harvard.edu header.i=@rowland.harvard.edu header.b="ONN9quwT" Received: by mail-qv1-f45.google.com with SMTP id 6a1803df08f44-709dc76b8a0so11031096d6.1 for ; Tue, 12 Aug 2025 13:06:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rowland.harvard.edu; s=google; t=1755029199; x=1755633999; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=eqkiQnb+v+DV7bwshJvcuqOvg6eI6sY8lksQaVEmngk=; b=ONN9quwT/wFuQ9Fihb4ymxfK5Qn+8rULdZmdvb12CWxefvol6wTSVidKp9x70Gaaqi 0C/a6pC12WK2TGCFTNq62g6HcpjuedYAMRso+yGxyab2UlKJaVgxkwBRIl0m1siSo93H T70DKdE0qCimZ5GffpKDvKQze13IXoZfjYeMHDtJLa963v/6Pmjl1MwHuSXZCUj9IjNu nLUAnVwbyndewRH7M693cA+Jsfwm/aJVQU9j768uB5YqloVeHA+NKqHznZ1V1VzXHd0Z VWL79B0ipIYtTJLIJgwIUWWN/uUQaWpjeiRGwCYaHxnZwHuW3bLDQttYRKh9bHVMmr6p KVvQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1755029199; x=1755633999; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=eqkiQnb+v+DV7bwshJvcuqOvg6eI6sY8lksQaVEmngk=; b=WgI3apRkylQh4ZRjVVGnfzKsiFOvEUy1qBcrGWnlkYqAhAub65eh0nxb2+ZI/HPB9U ugacvwpVoYqZ9blogtOihzE2/HE98JVYqUgp8E7YqBGhZ2q+jwHzLo85gg6rMdI8QHLR BrxSM0Ou5izvE9XvB4XXtiudJtBz7rUuAVcFAYG3ZTSG8LetfeMYdl/1rvT+oYHnO/Be 4SvYgCkAl1Lc6xJt6C/2J0FBP0PxBi9Y3IK98gw8IyWjjuA/ONteCYAXLKlYolyx/woi 4IIcSqEq77+ff4YP8zrXV3hHTE201AesPaWcXDyJxFVNrU5w1Jo0xVHgHdJvZ1rWEZk4 yerg== X-Forwarded-Encrypted: i=1; AJvYcCXs+8vovZZEclvUcgZJ+P6iIbUQ5yO0LZ6GK4C9o4tlYL1F3tpDvA/SQ1YRa0P2nokoMfqQXiNdaZ8=@vger.kernel.org X-Gm-Message-State: AOJu0YzbseO5w40J5LqAcG5LCCc05XywOdImV7uCHi7ZapdgkICpivyr hHzLahVW4aYDle3HFCZbhZ2QhjJx7wkqDOhxprrnO7m71pz/8R1TSLxGmyw87ro01Q== X-Gm-Gg: ASbGncucWtfZ7lYdFooW7F6tul0to/FGEIhO1bSvwPWvZbJCxPKNYRlaHGD4PZKa3VU NK2tPDL1677VoRuvxFYCvSeK3/pN2McRQTlElAoS8Oa4E9KQId2zDT+xt2BMB4cuMlLWEkOGZq1 UFgv5ar25YUi8lUhupHzqdPtVGWPWB3Y/NmtTMziBxQLi0lUHMHQO31aVss9dElVdaLv7UhwAJA 5J0VWHMAOktK3P6HtDHzDtcY+vvcidkenFlIjw9Gmeash8OU1Kjwp2qvbhoII30t2M92flQmbVc wA6IOS0jZSSuaOaUvUBNw6Ujn845laDyNvGT6epxFXKXTykb4xgvEQQ35+ctvakycbUmRW1CppC J/hsbKmnW+qkHCx7cI7aoyG0= X-Google-Smtp-Source: AGHT+IGGZlvv17fMp2WDnfMMFShmDsTlMM6IcnzKcbMc/Ggu/R7+9qwyKK0VohswEqNLATbAFPlTWg== X-Received: by 2002:a05:6214:29e6:b0:707:51a6:184f with SMTP id 6a1803df08f44-709e89fd871mr5029606d6.48.1755029198601; Tue, 12 Aug 2025 13:06:38 -0700 (PDT) Received: from rowland.harvard.edu ([2601:19b:681:fd10::e316]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-7077ca363fesm179978606d6.31.2025.08.12.13.06.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Aug 2025 13:06:38 -0700 (PDT) Date: Tue, 12 Aug 2025 16:06:35 -0400 From: Alan Stern To: Thorsten Blum Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, usb-storage@lists.one-eyed-alien.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH] usb: storage: realtek_cr: Simplify rts51x_bulk_transport() Message-ID: References: <20250812144358.122154-1-thorsten.blum@linux.dev> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250812144358.122154-1-thorsten.blum@linux.dev> On Tue, Aug 12, 2025 at 04:43:58PM +0200, Thorsten Blum wrote: > Change the function parameter 'buf_len' from 'int' to 'unsigned int' and > only update the local variable 'residue' if needed. > > Update the rts51x_read_status() function signature accordingly. That last part isn't really necessary, is it? It doesn't make the code any clearer, less buggy, or quicker to execute. > Signed-off-by: Thorsten Blum > --- > drivers/usb/storage/realtek_cr.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/usb/storage/realtek_cr.c b/drivers/usb/storage/realtek_cr.c > index 7dea28c2b8ee..8a4d7c0f2662 100644 > --- a/drivers/usb/storage/realtek_cr.c > +++ b/drivers/usb/storage/realtek_cr.c > @@ -199,7 +199,8 @@ static const struct us_unusual_dev realtek_cr_unusual_dev_list[] = { > #undef UNUSUAL_DEV > > static int rts51x_bulk_transport(struct us_data *us, u8 lun, > - u8 *cmd, int cmd_len, u8 *buf, int buf_len, > + u8 *cmd, int cmd_len, u8 *buf, > + unsigned int buf_len, > enum dma_data_direction dir, int *act_len) > { > struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *)us->iobuf; > @@ -260,8 +261,8 @@ static int rts51x_bulk_transport(struct us_data *us, u8 lun, > * try to compute the actual residue, based on how much data > * was really transferred and what the device tells us > */ > - if (residue) > - residue = residue < buf_len ? residue : buf_len; > + if (residue > buf_len) > + residue = buf_len; This really has nothing at all to do with whether buf_len is a signed quantity -- it should never be negative. (And I have no idea why the original code includes that test for residue being nonzero.) Much more serious is something you didn't change: Just above these lines it says: residue = bcs->Residue; It should say: residue = le32_to_cpu(bcs->Residue); Alan Stern