Re: [PATCHv2 22/28] cxusb: treat firmware data as const

From: Michael Krufky
Date: Sun May 25 2008 - 10:14:39 EST


David,

It's broken... Please see fix, below:

David Woodhouse wrote:
> ...which means allocating our own copy when we want to modify it.
>
> Signed-off-by: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
> ---
> drivers/media/dvb/dvb-usb/cxusb.c | 21 ++++++++++++++++++---
> 1 files changed, 18 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/dvb/dvb-usb/cxusb.c b/drivers/media/dvb/dvb-usb/cxusb.c
> index 720fcd1..94bb482 100644
> --- a/drivers/media/dvb/dvb-usb/cxusb.c
> +++ b/drivers/media/dvb/dvb-usb/cxusb.c
> @@ -24,6 +24,7 @@
> * see Documentation/dvb/README.dvb-usb for more information
> */
> #include <media/tuner.h>
> +#include <linux/vmalloc.h>
>
> #include "cxusb.h"
>
> @@ -700,12 +701,26 @@ static int bluebird_patch_dvico_firmware_download(struct usb_device *udev,
>
> if (fw->data[idoff] == (USB_VID_DVICO & 0xff) &&
> fw->data[idoff + 1] == USB_VID_DVICO >> 8) {
> - fw->data[idoff + 2] =
> + struct firmware new_fw;
> + u8 *new_fw_data = vmalloc(fw->size);
> + int ret;
> +
> + if (!new_fw_data)
> + return -ENOMEM;
> +
> + memcpy(new_fw_data, fw->data, fw->size);
> + new_fw.size = fw->size;
> + new_fw.data = fw->data;
> +
> + new_fw_data[idoff + 2] =
> le16_to_cpu(udev->descriptor.idProduct) + 1;
> - fw->data[idoff + 3] =
> + new_fw_data[idoff + 3] =
> le16_to_cpu(udev->descriptor.idProduct) >> 8;
>
> - return usb_cypress_load_firmware(udev, fw, CYPRESS_FX2);
> + ret = usb_cypress_load_firmware(udev, &new_fw,
> + CYPRESS_FX2);
> + vfree(new_fw_data);
> + return ret;
> }
> }
>
>
The unmodified firmware was being uploaded to the device, instead of the patched firmware :-(

After making this additional one-line change, the patch works fine.

Please feel free to fold this into your own patch.

Signed-off-by: Michael Krufky <mkrufky@xxxxxxxxxxx>

---
linux/drivers/media/dvb/dvb-usb/cxusb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/media/dvb/dvb-usb/cxusb.c
+++ b/drivers/media/dvb/dvb-usb/cxusb.c
@@ -710,7 +710,7 @@

memcpy(new_fw_data, fw->data, fw->size);
new_fw.size = fw->size;
- new_fw.data = fw->data;
+ new_fw.data = new_fw_data;

new_fw_data[idoff + 2] =
le16_to_cpu(udev->descriptor.idProduct) + 1;






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