Hi, Andrew,

The other two are correct because they intend to write multiple registers - they are used with a length parameter.

Ethan

On Sun, Dec 21, 2025 at 4:34 AM Andrew Lunn andrew@lunn.ch wrote:

On Sun, Dec 21, 2025 at 12:24:00AM -0800, Ethan Nelson-Moore wrote:

...

This fixes the device failing to initialize with "error reading MAC address" for me, probably because the incorrect write of NCR_RST to SR_NCR is not actually resetting the device.

Fixes: c9b37458e95629b1d1171457afdcc1bf1eb7881d ("USB2NET : SR9700 : One chip USB 1.1 USB2NET SR9700Device Driver Support") Cc: stable@vger.kernel.org Signed-off-by: Ethan Nelson-Moore enelsonmoore@gmail.com

---

drivers/net/usb/sr9700.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/usb/sr9700.c b/drivers/net/usb/sr9700.c index 091bc2aca7e8..5d97e95a17b0 100644 --- a/drivers/net/usb/sr9700.c +++ b/drivers/net/usb/sr9700.c @@ -52,7 +52,7 @@ static int sr_read_reg(struct usbnet *dev, u8 reg, u8 *value)

static int sr_write_reg(struct usbnet *dev, u8 reg, u8 value) {

• return usbnet_write_cmd(dev, SR_WR_REGS, SR_REQ_WR_REG,
  

• return usbnet_write_cmd(dev, SR_WR_REG, SR_REQ_WR_REG,
                          value, reg, NULL, 0);
  

}

@@ -65,7 +65,7 @@ static void sr_write_async(struct usbnet *dev, u8 reg, u16 length,

static void sr_write_reg_async(struct usbnet *dev, u8 reg, u8 value) {

• usbnet_write_cmd_async(dev, SR_WR_REGS, SR_REQ_WR_REG,
  

• usbnet_write_cmd_async(dev, SR_WR_REG, SR_REQ_WR_REG,
                         value, reg, NULL, 0);
  

}

I don't know anything about this hardware, but there are four calls using SR_WR_REG:

https://elixir.bootlin.com/linux/v6.18.2/source/drivers/net/usb/sr9700.h#L15...

You only change two here? Are the other two correct?

It might be worth while also changing the name of one of these:

#define SR_WR_REGS 0x01 #define SR_WR_REG 0x03

to make it clearer what each is actually used for, so they don't get used wrongly again.

    Andrew