[PATCH 1/4] net: e1000: add and make use of NUM_RX_DESC macro

[Ramon Fried]

On Fri, Mar 3, 2023 at 10:49 PM Christian Gmeiner
<christian.gmeiner at gmail.com> wrote:
>
> The call to DEFINE_ALIGN_BUFFER for the rx_desc array
> conained an icnonsistency as 16 receive descriptors
> were allocated when the remaining code would only use
> 8 of them.
>
> Signed-off-by: Christian Gmeiner <christian.gmeiner at gmail.com>
> ---
>  drivers/net/e1000.c | 6 +++---
>  drivers/net/e1000.h | 2 ++
>  2 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/e1000.c b/drivers/net/e1000.c
> index 41e6ba760e..8dccf29c7e 100644
> --- a/drivers/net/e1000.c
> +++ b/drivers/net/e1000.c
> @@ -60,7 +60,7 @@ tested on both gig copper and gig fiber boards
>   * move these buffers and the tx/rx pointers to struct e1000_hw.
>   */
>  DEFINE_ALIGN_BUFFER(struct e1000_tx_desc, tx_base, 16, E1000_BUFFER_ALIGN);
> -DEFINE_ALIGN_BUFFER(struct e1000_rx_desc, rx_base, 16, E1000_BUFFER_ALIGN);
> +DEFINE_ALIGN_BUFFER(struct e1000_rx_desc, rx_base, NUM_RX_DESC, E1000_BUFFER_ALIGN);
>  DEFINE_ALIGN_BUFFER(unsigned char, packet, 4096, E1000_BUFFER_ALIGN);
>
>  static int tx_tail;
> @@ -5095,7 +5095,7 @@ fill_rx(struct e1000_hw *hw)
>
>         rx_last = rx_tail;
>         rd = rx_base + rx_tail;
> -       rx_tail = (rx_tail + 1) % 8;
> +       rx_tail = (rx_tail + 1) % NUM_RX_DESC;
>         memset(rd, 0, 16);
>         rd->buffer_addr = cpu_to_le64(virt_to_phys(packet));
>
> @@ -5272,7 +5272,7 @@ e1000_configure_rx(struct e1000_hw *hw)
>         E1000_WRITE_REG(hw, RDBAL, lower_32_bits(virt_to_phys(rx_base)));
>         E1000_WRITE_REG(hw, RDBAH, upper_32_bits(virt_to_phys(rx_base)));
>
> -       E1000_WRITE_REG(hw, RDLEN, 128);
> +       E1000_WRITE_REG(hw, RDLEN, NUM_RX_DESC * sizeof(struct e1000_rx_desc));
>
>         /* Setup the HW Rx Head and Tail Descriptor Pointers */
>         E1000_WRITE_REG(hw, RDH, 0);
> diff --git a/drivers/net/e1000.h b/drivers/net/e1000.h
> index f788394da8..69882ba66f 100644
> --- a/drivers/net/e1000.h
> +++ b/drivers/net/e1000.h
> @@ -42,6 +42,8 @@
>  #define DEBUGOUT(fmt, args...) do { } while (0)
>  #endif
>
> +#define NUM_RX_DESC            8
> +
>  /* I/O wrapper functions */
>  #define E1000_WRITE_REG(a, reg, value) \
>         writel((value), ((a)->hw_addr + E1000_##reg))
> --
> 2.39.2
>
Reviewed-by: Ramon Fried <rfried.dev at gmail.com>