On Sun, Jan 03, 2021 at 04:19:02PM +0800, qiang.zhang@xxxxxxxxxxxxx wrote:
> From: Zqiang <qiang.zhang@xxxxxxxxxxxxx>
>
> When USB hosts just use PIO, allocate memory by slab/slub
> memory manager, if the required memory size is larger than
> one or more page sizes, need allocate memory directly from
> buddy systems.
That says _what_ you are doing, but not _why_ you need to do this.
What in-tree host controller has this problem and on what platform?
>
> Signed-off-by: Zqiang <qiang.zhang@xxxxxxxxxxxxx>
> ---
> drivers/usb/core/buffer.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
> index fbb087b728dc..28e7db9f93d5 100644
> --- a/drivers/usb/core/buffer.c
> +++ b/drivers/usb/core/buffer.c
> @@ -131,7 +131,8 @@ void *hcd_buffer_alloc(
> /* some USB hosts just use PIO */
> if (!hcd_uses_dma(hcd)) {
> *dma = ~(dma_addr_t) 0;
> - return kmalloc(size, mem_flags);
> + return size < PAGE_SIZE ? kmalloc(size, mem_flags)
> + : __get_free_pages(mem_flags, get_order(size));
Please never use ? : statements if at all possible. Use a real if ()
instead.
Oh, and make sure your code actually builds properly :(
What platforms did you test this on?
thanks,
greg k-h
