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 179DD158201; Tue, 9 Jul 2024 11:28:59 +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=1720524539; cv=none; b=fzJBF2+PERkPs1mMxI7kQGmGNeyPXJPa34O+QwIFfGyIuIjPbjmWCf9PtTbxk/tAXGYXHR84nhfHsNqnpyPxY/ARLmRNirq0bdfD1QdUxlo1avvbcZgwSwO/Hh17dFsA6okvHDHMsOnbHn2xISr4XMY0oFgNnfyIcnC0jCfG1Ug= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720524539; c=relaxed/simple; bh=EJiGuGyJ4aRzoiFhAqPKq2PO+cz1NQp7DFSY3BMTlBY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=entdhNsegpmGkNUxu3Kpc2/G14kSmFTbdbT9Q2R2lDdZA8Ja9BRT2sVnwlASluvdzYmEQ4fGYUcFYfANH4pWsGVdy7Yo70d/bLzRTy9O4ActOnJpv6vCnMvMED7uL9kf8esAyeipfixwiHLKOzCO3OwDgBdOzJ2Foi/nz4imkaI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=jqnzuogg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="jqnzuogg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8A18CC3277B; Tue, 9 Jul 2024 11:28:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1720524538; bh=EJiGuGyJ4aRzoiFhAqPKq2PO+cz1NQp7DFSY3BMTlBY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jqnzuogg2WRX2ES9rgTTgDTsmw7at4fhufwIbt77TV11qyGlrPOfpf2rFOsj70ibR bLcPgGRKs5Iff8yXKokkUbwzJyHW4pvRaWWTk/2liiAnP0Ndlxa4U3HYD65c2Vv+IV BR22STg8s82IDtI+RzrUQteCEtzmLuerO6wArJA0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Michael Bunk , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 6.1 017/102] media: dw2102: Dont translate i2c read into write Date: Tue, 9 Jul 2024 13:09:40 +0200 Message-ID: <20240709110652.040462012@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240709110651.353707001@linuxfoundation.org> References: <20240709110651.353707001@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Bunk [ Upstream commit 0e148a522b8453115038193e19ec7bea71403e4a ] The code ignored the I2C_M_RD flag on I2C messages. Instead it assumed an i2c transaction with a single message must be a write operation and a transaction with two messages would be a read operation. Though this works for the driver code, it leads to problems once the i2c device is exposed to code not knowing this convention. For example, I did "insmod i2c-dev" and issued read requests from userspace, which were translated into write requests and destroyed the EEPROM of my device. So, just check and respect the I2C_M_READ flag, which indicates a read when set on a message. If it is absent, it is a write message. Incidentally, changing from the case statement to a while loop allows the code to lift the limitation to two i2c messages per transaction. There are 4 more *_i2c_transfer functions affected by the same behaviour and limitation that should be fixed in the same way. Link: https://lore.kernel.org/linux-media/20220116112238.74171-2-micha@freedict.org Signed-off-by: Michael Bunk Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/usb/dvb-usb/dw2102.c | 120 ++++++++++++++++++----------- 1 file changed, 73 insertions(+), 47 deletions(-) diff --git a/drivers/media/usb/dvb-usb/dw2102.c b/drivers/media/usb/dvb-usb/dw2102.c index 356fc728d59a8..0da3e83389d7a 100644 --- a/drivers/media/usb/dvb-usb/dw2102.c +++ b/drivers/media/usb/dvb-usb/dw2102.c @@ -716,6 +716,7 @@ static int su3000_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[], { struct dvb_usb_device *d = i2c_get_adapdata(adap); struct dw2102_state *state; + int j; if (!d) return -ENODEV; @@ -729,11 +730,11 @@ static int su3000_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[], return -EAGAIN; } - switch (num) { - case 1: - switch (msg[0].addr) { + j = 0; + while (j < num) { + switch (msg[j].addr) { case SU3000_STREAM_CTRL: - state->data[0] = msg[0].buf[0] + 0x36; + state->data[0] = msg[j].buf[0] + 0x36; state->data[1] = 3; state->data[2] = 0; if (dvb_usb_generic_rw(d, state->data, 3, @@ -745,61 +746,86 @@ static int su3000_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[], if (dvb_usb_generic_rw(d, state->data, 1, state->data, 2, 0) < 0) err("i2c transfer failed."); - msg[0].buf[1] = state->data[0]; - msg[0].buf[0] = state->data[1]; + msg[j].buf[1] = state->data[0]; + msg[j].buf[0] = state->data[1]; break; default: - if (3 + msg[0].len > sizeof(state->data)) { - warn("i2c wr: len=%d is too big!\n", - msg[0].len); + /* if the current write msg is followed by a another + * read msg to/from the same address + */ + if ((j+1 < num) && (msg[j+1].flags & I2C_M_RD) && + (msg[j].addr == msg[j+1].addr)) { + /* join both i2c msgs to one usb read command */ + if (4 + msg[j].len > sizeof(state->data)) { + warn("i2c combined wr/rd: write len=%d is too big!\n", + msg[j].len); + num = -EOPNOTSUPP; + break; + } + if (1 + msg[j+1].len > sizeof(state->data)) { + warn("i2c combined wr/rd: read len=%d is too big!\n", + msg[j+1].len); + num = -EOPNOTSUPP; + break; + } + + state->data[0] = 0x09; + state->data[1] = msg[j].len; + state->data[2] = msg[j+1].len; + state->data[3] = msg[j].addr; + memcpy(&state->data[4], msg[j].buf, msg[j].len); + + if (dvb_usb_generic_rw(d, state->data, msg[j].len + 4, + state->data, msg[j+1].len + 1, 0) < 0) + err("i2c transfer failed."); + + memcpy(msg[j+1].buf, &state->data[1], msg[j+1].len); + j++; + break; + } + + if (msg[j].flags & I2C_M_RD) { + /* single read */ + if (1 + msg[j].len > sizeof(state->data)) { + warn("i2c rd: len=%d is too big!\n", msg[j].len); + num = -EOPNOTSUPP; + break; + } + + state->data[0] = 0x09; + state->data[1] = 0; + state->data[2] = msg[j].len; + state->data[3] = msg[j].addr; + memcpy(&state->data[4], msg[j].buf, msg[j].len); + + if (dvb_usb_generic_rw(d, state->data, 4, + state->data, msg[j].len + 1, 0) < 0) + err("i2c transfer failed."); + + memcpy(msg[j].buf, &state->data[1], msg[j].len); + break; + } + + /* single write */ + if (3 + msg[j].len > sizeof(state->data)) { + warn("i2c wr: len=%d is too big!\n", msg[j].len); num = -EOPNOTSUPP; break; } - /* always i2c write*/ state->data[0] = 0x08; - state->data[1] = msg[0].addr; - state->data[2] = msg[0].len; + state->data[1] = msg[j].addr; + state->data[2] = msg[j].len; - memcpy(&state->data[3], msg[0].buf, msg[0].len); + memcpy(&state->data[3], msg[j].buf, msg[j].len); - if (dvb_usb_generic_rw(d, state->data, msg[0].len + 3, + if (dvb_usb_generic_rw(d, state->data, msg[j].len + 3, state->data, 1, 0) < 0) err("i2c transfer failed."); + } // switch + j++; - } - break; - case 2: - /* always i2c read */ - if (4 + msg[0].len > sizeof(state->data)) { - warn("i2c rd: len=%d is too big!\n", - msg[0].len); - num = -EOPNOTSUPP; - break; - } - if (1 + msg[1].len > sizeof(state->data)) { - warn("i2c rd: len=%d is too big!\n", - msg[1].len); - num = -EOPNOTSUPP; - break; - } - - state->data[0] = 0x09; - state->data[1] = msg[0].len; - state->data[2] = msg[1].len; - state->data[3] = msg[0].addr; - memcpy(&state->data[4], msg[0].buf, msg[0].len); - - if (dvb_usb_generic_rw(d, state->data, msg[0].len + 4, - state->data, msg[1].len + 1, 0) < 0) - err("i2c transfer failed."); - - memcpy(msg[1].buf, &state->data[1], msg[1].len); - break; - default: - warn("more than 2 i2c messages at a time is not handled yet."); - break; - } + } // while mutex_unlock(&d->data_mutex); mutex_unlock(&d->i2c_mutex); return num; -- 2.43.0