Re: [PATCH v4 1/3] net: dsa: microchip: implement KSZ87xx Module 3 low-loss cable errata
From: Marek Vasut
Date: Fri Apr 17 2026 - 10:41:24 EST
On 4/17/26 2:44 PM, Fidelio Lawson wrote:
[...]
@@ -1271,6 +1287,29 @@ int ksz8_w_phy(struct ksz_device *dev, u16 phy, u16 reg, u16 val)Do these values need some check, so they would be in the correct range(s) / in the correct bitfields before being written into those registers ?
if (ret)
return ret;
break;
+ case PHY_REG_KSZ87XX_SHORT_CABLE:
+ if (!ksz_is_ksz87xx(dev))
+ return -EOPNOTSUPP;
+ ret = ksz87xx_apply_low_loss_preset(dev, !!val);
+ if (ret)
+ return ret;
+ break;
+ case PHY_REG_KSZ87XX_LPF_BW:
+ if (!ksz_is_ksz87xx(dev))
+ return -EOPNOTSUPP;
+ ret = ksz8_ind_write8(dev, TABLE_LINK_MD, KSZ87XX_REG_PHY_LPF, (u8)val);
+ if (ret)
+ return ret;
+ dev->lpf_bw = val;
+ break;
+ case PHY_REG_KSZ87XX_EQ_INIT:
+ if (!ksz_is_ksz87xx(dev))
+ return -EOPNOTSUPP;
+ ret = ksz8_ind_write8(dev, TABLE_LINK_MD, KSZ87XX_REG_DSP_EQ, (u8)val);