Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752260Ab1CTVwy (ORCPT ); Sun, 20 Mar 2011 17:52:54 -0400 Received: from ist.d-labs.de ([213.239.218.44]:51951 "EHLO mx01.d-labs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751438Ab1CTVvd (ORCPT ); Sun, 20 Mar 2011 17:51:33 -0400 From: Florian Mickler To: mchehab@infradead.org Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, crope@iki.fi, tvboxspy@gmail.com, Florian Mickler Subject: [PATCH 3/5] [media] au6610: get rid of on-stack dma buffer Date: Sun, 20 Mar 2011 22:50:50 +0100 Message-Id: <1300657852-29318-4-git-send-email-florian@mickler.org> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1300657852-29318-1-git-send-email-florian@mickler.org> References: <1300657852-29318-1-git-send-email-florian@mickler.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2250 Lines: 75 usb_control_msg initiates (and waits for completion of) a dma transfer using the supplied buffer. That buffer thus has to be seperately allocated on the heap. In lib/dma_debug.c the function check_for_stack even warns about it: WARNING: at lib/dma-debug.c:866 check_for_stack Signed-off-by: Florian Mickler Acked-by: Antti Palosaari Reviewed-by: Antti Palosaari Tested-by: Antti Palosaari --- drivers/media/dvb/dvb-usb/au6610.c | 22 ++++++++++++++++------ 1 files changed, 16 insertions(+), 6 deletions(-) diff --git a/drivers/media/dvb/dvb-usb/au6610.c b/drivers/media/dvb/dvb-usb/au6610.c index eb34cc3..2351077 100644 --- a/drivers/media/dvb/dvb-usb/au6610.c +++ b/drivers/media/dvb/dvb-usb/au6610.c @@ -33,8 +33,16 @@ static int au6610_usb_msg(struct dvb_usb_device *d, u8 operation, u8 addr, { int ret; u16 index; - u8 usb_buf[6]; /* enough for all known requests, - read returns 5 and write 6 bytes */ + u8 *usb_buf; + + /* + * allocate enough for all known requests, + * read returns 5 and write 6 bytes + */ + usb_buf = kmalloc(6, GFP_KERNEL); + if (!usb_buf) + return -ENOMEM; + switch (wlen) { case 1: index = wbuf[0] << 8; @@ -45,14 +53,15 @@ static int au6610_usb_msg(struct dvb_usb_device *d, u8 operation, u8 addr, break; default: warn("wlen = %x, aborting.", wlen); - return -EINVAL; + ret = -EINVAL; + goto error; } ret = usb_control_msg(d->udev, usb_rcvctrlpipe(d->udev, 0), operation, USB_TYPE_VENDOR|USB_DIR_IN, addr << 1, index, - usb_buf, sizeof(usb_buf), AU6610_USB_TIMEOUT); + usb_buf, 6, AU6610_USB_TIMEOUT); if (ret < 0) - return ret; + goto error; switch (operation) { case AU6610_REQ_I2C_READ: @@ -60,7 +69,8 @@ static int au6610_usb_msg(struct dvb_usb_device *d, u8 operation, u8 addr, /* requested value is always 5th byte in buffer */ rbuf[0] = usb_buf[4]; } - +error: + kfree(usb_buf); return ret; } -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/