From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:33348 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1763259AbdDSMur (ORCPT ); Wed, 19 Apr 2017 08:50:47 -0400 Subject: Patch "[media] cxusb: Use a dma capable buffer also for reading" has been added to the 4.10-stable tree To: stefan.bruens@rwth-aachen.de, ben@decadent.org.uk, gregkh@linuxfoundation.org, mchehab@s-opensource.com, spender@grsecurity.net Cc: , From: Date: Wed, 19 Apr 2017 14:50:32 +0200 Message-ID: <1492606232213136@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled [media] cxusb: Use a dma capable buffer also for reading to the 4.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: cxusb-use-a-dma-capable-buffer-also-for-reading.patch and it can be found in the queue-4.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 3f190e3aec212fc8c61e202c51400afa7384d4bc Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Stefan=20Br=C3=BCns?= Date: Sun, 5 Feb 2017 12:57:59 -0200 Subject: [media] cxusb: Use a dma capable buffer also for reading MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Stefan Brüns commit 3f190e3aec212fc8c61e202c51400afa7384d4bc upstream. Commit 17ce039b4e54 ("[media] cxusb: don't do DMA on stack") added a kmalloc'ed bounce buffer for writes, but missed to do the same for reads. As the read only happens after the write is finished, we can reuse the same buffer. As dvb_usb_generic_rw handles a read length of 0 by itself, avoid calling it using the dvb_usb_generic_read wrapper function. Signed-off-by: Stefan Brüns Signed-off-by: Mauro Carvalho Chehab Cc: Ben Hutchings Cc: Brad Spengler Signed-off-by: Greg Kroah-Hartman --- drivers/media/usb/dvb-usb/cxusb.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) --- a/drivers/media/usb/dvb-usb/cxusb.c +++ b/drivers/media/usb/dvb-usb/cxusb.c @@ -59,23 +59,24 @@ static int cxusb_ctrl_msg(struct dvb_usb u8 cmd, u8 *wbuf, int wlen, u8 *rbuf, int rlen) { struct cxusb_state *st = d->priv; - int ret, wo; + int ret; if (1 + wlen > MAX_XFER_SIZE) { warn("i2c wr: len=%d is too big!\n", wlen); return -EOPNOTSUPP; } - wo = (rbuf == NULL || rlen == 0); /* write-only */ + if (rlen > MAX_XFER_SIZE) { + warn("i2c rd: len=%d is too big!\n", rlen); + return -EOPNOTSUPP; + } mutex_lock(&d->data_mutex); st->data[0] = cmd; memcpy(&st->data[1], wbuf, wlen); - if (wo) - ret = dvb_usb_generic_write(d, st->data, 1 + wlen); - else - ret = dvb_usb_generic_rw(d, st->data, 1 + wlen, - rbuf, rlen, 0); + ret = dvb_usb_generic_rw(d, st->data, 1 + wlen, st->data, rlen, 0); + if (!ret && rbuf && rlen) + memcpy(rbuf, st->data, rlen); mutex_unlock(&d->data_mutex); return ret; Patches currently in stable-queue which might be from stefan.bruens@rwth-aachen.de are queue-4.10/cxusb-use-a-dma-capable-buffer-also-for-reading.patch