[PATCH] Remove large struct from the stack in USB storage isd200 driver

From: imunsie
Date: Tue Mar 02 2010 - 19:01:08 EST

From: Ian Munsie <imunsie@xxxxxxxxxx>

The compiler throws the following warning when compiling for a PowerPC 64
bit machine:

drivers/usb/storage/isd200.c:580: warning: the frame size of 2208 bytes is larger than 2048 bytes

There is a struct scsi_device which is placed on the stack and is
largely responsible for such wastage. The struct is just a dummy struct
filled with NULLs and set as the scsi_cmnd->device to make the
usb_stor_Bulk_transport function happy.

This patch makes the struct static, so that it is never placed onto the
stack and silences the compiler warning.

Signed-off-by: Ian Munsie <imunsie@xxxxxxxxxx>
drivers/usb/storage/isd200.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/storage/isd200.c b/drivers/usb/storage/isd200.c
index fdba2f6..e9cbc14 100644
--- a/drivers/usb/storage/isd200.c
+++ b/drivers/usb/storage/isd200.c
@@ -490,13 +490,13 @@ static int isd200_action( struct us_data *us, int action,
void* pointer, int value )
union ata_cdb ata;
- struct scsi_device srb_dev;
+ /* static to prevent this large struct being placed on the valuable stack */
+ static struct scsi_device srb_dev;
struct isd200_info *info = (struct isd200_info *)us->extra;
struct scsi_cmnd *srb = &info->srb;
int status;

memset(&ata, 0, sizeof(ata));
- memset(&srb_dev, 0, sizeof(srb_dev));
srb->cmnd = info->cmnd;
srb->device = &srb_dev;

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