lkml.org 
[lkml]   [2015]   [Mar]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] ath9k_htc: avoid memcpy when downloading firmware
From
Date
On Tue, 2015-03-03 at 12:24 +0800, Fred Chou wrote:
> From: Fred Chou <fred.chou.nd@gmail.com>
>
> The temporary buffer to hold firmware data is not really needed,
> and memcpy can be avoided by using data pointer instead.
>
> Signed-off-by: Fred Chou <fred.chou.nd@gmail.com>
> ---
> drivers/net/wireless/ath/ath9k/hif_usb.c | 12 ++----------
> 1 file changed, 2 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
> index 10c02f5..0bc35a8 100644
> --- a/drivers/net/wireless/ath/ath9k/hif_usb.c
> +++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
> @@ -986,30 +986,22 @@ static int ath9k_hif_usb_download_fw(struct hif_device_usb *hif_dev)
> const void *data = hif_dev->fw_data;

Here data can be vmalloc() backed.

> size_t len = hif_dev->fw_size;
> u32 addr = AR9271_FIRMWARE;
> - u8 *buf = kzalloc(4096, GFP_KERNEL);

Here buf is kmalloc() backed.

> u32 firm_offset;
>
> - if (!buf)
> - return -ENOMEM;
> -
> while (len) {
> transfer = min_t(size_t, len, 4096);
> - memcpy(buf, data, transfer);
>
> err = usb_control_msg(hif_dev->udev,
> usb_sndctrlpipe(hif_dev->udev, 0),
> FIRMWARE_DOWNLOAD, 0x40 | USB_DIR_OUT,
> - addr >> 8, 0, buf, transfer, HZ);


Are you sure usb_control_msg() accepts vmalloc()ed buffers ?

My guess is the answer is no.




\
 
 \ /
  Last update: 2015-03-03 07:21    [W:0.034 / U:0.132 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site