From nobody Mon Nov 25 02:46:46 2024 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.4]) by smtp.subspace.kernel.org (Postfix) with ESMTP id BC72E14F90; Wed, 30 Oct 2024 08:40:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.4 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730277625; cv=none; b=Eo7953bO+cHosNqCd2jHQs7bn1wCDLZlTEjcP8TZ4yY+aYx7aBiL/nOoSWrqqsAl0XjT41fJJ7UNjm7Y9aNTQHFWZu1GPPmkIqlm6HrdzrdlsbTL4Kfzx4lMz0Rf7bn/m+F35rfOeBHblaI5e5vrc1OKJTMSvpU/56WyJtuZ8jE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730277625; c=relaxed/simple; bh=yaqg8Rnxe/N+fm8iBLzgPBDiWo6/VJYvd9F3ySBL2hA=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=QtyORAizNKQVf6Yrr1YVXJ1JqW8sb8j/3u91d6zil8zLRE+5l4P8XdZ1TScyDCOd9BIot2rKKG5DtTEcKNW82jMcECNUFSc1ShM4Q0v78RueGQvozmoHFwFHZu7T5EpizL8K4oQTKp4ClCX1OxD3PmUDLbxslGef/7rv+uQPoew= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=lCka1MBY; arc=none smtp.client-ip=220.197.31.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="lCka1MBY" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=rc77A IZnH6tV5UZgxVycG9R3Z5ku1bY+hII0hTHlR9o=; b=lCka1MBYih2QtZjj0TN+a V50MDihoYg9UfUvvwugWFQlcAO76fKT/uD67mw+lVuq/zILCKGeGc6shAXZiMAaD XkInW0+ado6GvyNJX+1JWdOTLQN7hcdI0OthRsclqn1K+PglFu2pk8Ee+YZvVyPw DjnkXAcGIDxnG50k9TtXDQ= Received: from localhost.localdomain (unknown [192.19.38.250]) by gzga-smtp-mtada-g1-1 (Coremail) with SMTP id _____wCXvgzl8CFnap+qEQ--.1837S2; Wed, 30 Oct 2024 16:40:08 +0800 (CST) From: Dingyan Li <18500469033@163.com> To: gregkh@linuxfoundation.org, stern@rowland.harvard.edu Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, usb-storage@lists.one-eyed-alien.net Subject: [PATCH v1] usb: storage: add a macro for the upper limit of max LUN Date: Wed, 30 Oct 2024 16:38:58 +0800 Message-Id: <20241030083858.46907-1-18500469033@163.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: _____wCXvgzl8CFnap+qEQ--.1837S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxGw15Aw47WrykWr48JrW5Wrg_yoW5ZrW7pa 15AFW3Ar10qrsavrWkAw4fZFyrAws7KFyUKrZrK398XFsxAFyrJr18AFZY9FW3JrW7AF4I vFs0gry3W3yku3JanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07jnhL8UUUUU= X-CM-SenderInfo: jprykiiquwmiitt6il2tof0z/1tbioB+Iy2ch4afX5QABsP Content-Type: text/plain; charset="utf-8" The meaning of this value is already used in several places, but with constant values and comments to explain it separately. It's better to have a central place to do this then use the macro in those places for better readability. Signed-off-by: Dingyan Li <18500469033@163.com> --- drivers/usb/gadget/function/f_tcm.c | 8 ++------ drivers/usb/gadget/function/storage_common.h | 2 +- drivers/usb/storage/transport.c | 8 ++------ include/linux/usb/storage.h | 8 ++++++++ 4 files changed, 13 insertions(+), 13 deletions(-) diff --git a/drivers/usb/gadget/function/f_tcm.c b/drivers/usb/gadget/funct= ion/f_tcm.c index 15bb3aa12aa8..e1914b20f816 100644 --- a/drivers/usb/gadget/function/f_tcm.c +++ b/drivers/usb/gadget/function/f_tcm.c @@ -441,14 +441,10 @@ static int usbg_bot_setup(struct usb_function *f, pr_err("No LUNs configured?\n"); return -EINVAL; } - /* - * If 4 LUNs are present we return 3 i.e. LUN 0..3 can be - * accessed. The upper limit is 0xf - */ luns--; - if (luns > 0xf) { + if (luns > US_BULK_MAX_LUN_LIMIT) { pr_info_once("Limiting the number of luns to 16\n"); - luns =3D 0xf; + luns =3D US_BULK_MAX_LUN_LIMIT; } ret_lun =3D cdev->req->buf; *ret_lun =3D luns; diff --git a/drivers/usb/gadget/function/storage_common.h b/drivers/usb/gad= get/function/storage_common.h index ced5d2b09234..11ac785d5eee 100644 --- a/drivers/usb/gadget/function/storage_common.h +++ b/drivers/usb/gadget/function/storage_common.h @@ -131,7 +131,7 @@ static inline bool fsg_lun_is_open(struct fsg_lun *curl= un) #define FSG_BUFLEN ((u32)16384) =20 /* Maximal number of LUNs supported in mass storage function */ -#define FSG_MAX_LUNS 16 +#define FSG_MAX_LUNS (US_BULK_MAX_LUN_LIMIT + 1) =20 enum fsg_buffer_state { BUF_STATE_SENDING =3D -2, diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transpor= t.c index 9d767f6bf722..e6bc8ecaecbb 100644 --- a/drivers/usb/storage/transport.c +++ b/drivers/usb/storage/transport.c @@ -1087,13 +1087,9 @@ int usb_stor_Bulk_max_lun(struct us_data *us) usb_stor_dbg(us, "GetMaxLUN command result is %d, data is %d\n", result, us->iobuf[0]); =20 - /* - * If we have a successful request, return the result if valid. The - * CBW LUN field is 4 bits wide, so the value reported by the device - * should fit into that. - */ + /* If we have a successful request, return the result if valid. */ if (result > 0) { - if (us->iobuf[0] < 16) { + if (us->iobuf[0] <=3D US_BULK_MAX_LUN_LIMIT) { return us->iobuf[0]; } else { dev_info(&us->pusb_intf->dev, diff --git a/include/linux/usb/storage.h b/include/linux/usb/storage.h index 8539956bc2be..51be3bb8fccb 100644 --- a/include/linux/usb/storage.h +++ b/include/linux/usb/storage.h @@ -82,4 +82,12 @@ struct bulk_cs_wrap { #define US_BULK_RESET_REQUEST 0xff #define US_BULK_GET_MAX_LUN 0xfe =20 +/* + * If 4 LUNs are supported then the LUNs would be + * numbered from 0 to 3, and the return value for + * US_BULK_GET_MAX_LUN request would be 3. The valid + * LUN field is 4 bits wide, the upper limit is 0x0f. + */ +#define US_BULK_MAX_LUN_LIMIT 0x0f + #endif --=20 2.25.1