Re: [RFC PATCH net-next 3/6] net: ethernet: implement OA TC6 configuration function

From: Andrew Lunn
Date: Wed Sep 13 2023 - 20:46:27 EST


> +int oa_tc6_configure(struct oa_tc6 *tc6, u8 cps, bool ctrl_prot, bool tx_cut_thr,
> + bool rx_cut_thr)
> +{
> + u32 regval;
> + int ret;
> +
> + /* Read and configure the IMASK0 register for unmasking the interrupts */
> + ret = oa_tc6_read_register(tc6, OA_TC6_IMASK0, &regval, 1);
> + if (ret)
> + return ret;
> +
> + regval &= TXPEM & TXBOEM & TXBUEM & RXBOEM & LOFEM & HDREM;
> + ret = oa_tc6_write_register(tc6, OA_TC6_IMASK0, &regval, 1);

It is not so obvious what this 1 means. Maybe change to regval[1], and
user ARRAY_SIZE(). What also does not help is the function name,
oa_tc6_write_register(). Singular. So it appears to write one register,
not multiple registers. It might even make sense to make
oa_tc6_write_register() truly access a single register, and add
oa_tc6_write_registers() for multiple registers.

> +/* Unmasking interrupt fields in IMASK0 */
> +#define HDREM ~BIT(5) /* Header Error Mask */
> +#define LOFEM ~BIT(4) /* Loss of Framing Error Mask */
> +#define RXBOEM ~BIT(3) /* Rx Buffer Overflow Error Mask */
> +#define TXBUEM ~BIT(2) /* Tx Buffer Underflow Error Mask */
> +#define TXBOEM ~BIT(1) /* Tx Buffer Overflow Error Mask */
> +#define TXPEM ~BIT(0) /* Tx Protocol Error Mask */

Using ~BIT(X) is very usual. I would not do this, Principle of Least
Surprise.

> struct oa_tc6 {
> - struct spi_device *spi;
> - bool ctrl_prot;
> + struct completion rst_complete;
> struct task_struct *tc6_task;
> wait_queue_head_t tc6_wq;
> + struct spi_device *spi;
> + bool tx_cut_thr;
> + bool rx_cut_thr;
> + bool ctrl_prot;
> bool int_flag;
> - struct completion rst_complete;
> + u8 cps;
> };

Please try not to move stuff around. It makes the diff bigger than it
should be.

Andrew