On Tue, 10 Oct 2017 14:32:56 +1100
Cyril Bur <cyril...@gmail.com> wrote:
> Because the MTD core might split up a read() or write() from userspace
> into several calls to the driver, we may fail to get a token but already
> have done some work, best to return -EINTR back to userspace and have
> them decide what to do.
>
> Signed-off-by: Cyril Bur <cyril...@gmail.com>
Acked-by: Boris Brezillon <boris.brezil...@free-electrons.com>
> ---
> drivers/mtd/devices/powernv_flash.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/mtd/devices/powernv_flash.c
> b/drivers/mtd/devices/powernv_flash.c
> index 4dd3b5d2feb2..3343d4f5c4f3 100644
> --- a/drivers/mtd/devices/powernv_flash.c
> +++ b/drivers/mtd/devices/powernv_flash.c
> @@ -47,6 +47,11 @@ enum flash_op {
> FLASH_OP_ERASE,
> };
>
> +/*
> + * Don't return -ERESTARTSYS if we can't get a token, the MTD core
> + * might have split up the call from userspace and called into the
> + * driver more than once, we'll already have done some amount of work.
> + */
> static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op,
> loff_t offset, size_t len, size_t *retlen, u_char *buf)
> {
> @@ -63,6 +68,8 @@ static int powernv_flash_async_op(struct mtd_info *mtd,
> enum flash_op op,
> if (token < 0) {
> if (token != -ERESTARTSYS)
> dev_err(dev, "Failed to get an async token\n");
> + else
> + token = -EINTR;
> return token;
> }
>
