RE: [PATCH v2 2/2] net: ethernet: Add driver for Sunplus SP7021
From: Wells Lu 呂芳騰 <hidden>
Date: 2021-11-26 19:25:46
Also in:
lkml, netdev
From: Wells Lu 呂芳騰 <hidden>
Date: 2021-11-26 19:25:46
Also in:
lkml, netdev
Hi Andrew, I read specification of ICPlus IP101G (10M/100M PHY). Bits of register 0 (control) and register 1 (status) are R/W or RO type. They will not be cleared after read. No matter how many times they are read, the read-back value is the same. For example, Value of register 0 (control) is 0x3100 Value of register 1 (status) is 0x786d The read-back values are always the same unless you unplug the cable. Besides, we use polling mode (phydev->irq = PHY_POLL) PHY state-machine is triggered by using 1-Hz work- queue, not interrupt. We didn't find any problem after many tests after using 'force' mode. Can we go with this approach? Best regards, Wells
quoted
Hi Andrew, From data provided by ASIC engineer, MAC of SP7021 only reads the 4 registers of PHY: 0: Control register 1: Status registerThis is the register which has latching of the link status. genphy_update_link() expects this latching behaviour, and if the hardware reads the register, that behaviour is not going to happen. Andrew