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[3.11.y.z,extended,stable] Patch "[media] tuner-xc2028: Don't use dynamic static allocation" has been added to staging queue

Message ID 1386242679-2020-1-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques Dec. 5, 2013, 11:24 a.m. UTC 
This is a note to let you know that I have just added a patch titled

    [media] tuner-xc2028: Don't use dynamic static allocation

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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From e431092a5bc8792e282ec533da5e928ca573af53 Mon Sep 17 00:00:00 2001
From: Mauro Carvalho Chehab <m.chehab@samsung.com>
Date: Sat, 2 Nov 2013 06:13:11 -0300
Subject: [media] tuner-xc2028: Don't use dynamic static allocation

commit 56ac033725ec93a45170caf3979eb2b1211a59a8 upstream.

Dynamic static allocation is evil, as Kernel stack is too low, and
compilation complains about it on some archs:
	drivers/media/tuners/tuner-xc2028.c:651:1: warning: 'load_firmware' uses dynamic stack allocation [enabled by default]
Instead, let's enforce a limit for the buffer.
In the specific case of this driver, the maximum limit is 80, used only
on tm6000 driver. This limit is due to the size of the USB control URBs.
Ok, it would be theoretically possible to use a bigger size on PCI
devices, but the firmware load time is already good enough. Anyway,
if some usage requires more, it is just a matter of also increasing
the buffer size at load_firmware().

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 drivers/media/tuners/tuner-xc2028.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

--
1.8.3.2
diff mbox

Patch

diff --git a/drivers/media/tuners/tuner-xc2028.c b/drivers/media/tuners/tuner-xc2028.c
index 878d2c4..9771cd8 100644
--- a/drivers/media/tuners/tuner-xc2028.c
+++ b/drivers/media/tuners/tuner-xc2028.c
@@ -24,6 +24,9 @@ 
 #include <linux/dvb/frontend.h>
 #include "dvb_frontend.h"

+/* Max transfer size done by I2C transfer functions */
+#define MAX_XFER_SIZE  80
+
 /* Registers (Write-only) */
 #define XREG_INIT         0x00
 #define XREG_RF_FREQ      0x02
@@ -547,7 +550,10 @@  static int load_firmware(struct dvb_frontend *fe, unsigned int type,
 {
 	struct xc2028_data *priv = fe->tuner_priv;
 	int                pos, rc;
-	unsigned char      *p, *endp, buf[priv->ctrl.max_len];
+	unsigned char      *p, *endp, buf[MAX_XFER_SIZE];
+
+	if (priv->ctrl.max_len > sizeof(buf))
+		priv->ctrl.max_len = sizeof(buf);

 	tuner_dbg("%s called\n", __func__);