From: Lukas Wunner lukas@wunner.de
[ Upstream commit 3108871f19221372b251f7da1ac38736928b5b3a ]
Upon receiving data from the Interrupt Endpoint, the SMSC LAN95xx driver attempts to clear the signaled interrupts by writing "all ones" to the Interrupt Status Register.
However the driver only ever enables a single type of interrupt, namely the PHY Interrupt. And according to page 119 of the LAN950x datasheet, its bit in the Interrupt Status Register is read-only. There's no other way to clear it than in a separate PHY register:
https://www.microchip.com/content/dam/mchp/documents/UNG/ProductDocuments/Da...
Consequently, writing "all ones" to the Interrupt Status Register is pointless and can be dropped.
Tested-by: Oleksij Rempel o.rempel@pengutronix.de # LAN9514/9512/9500 Tested-by: Ferry Toth fntoth@gmail.com # LAN9514 Signed-off-by: Lukas Wunner lukas@wunner.de Reviewed-by: Andrew Lunn andrew@lunn.ch Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/usb/smsc95xx.c | 4 ---- 1 file changed, 4 deletions(-)
diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c index 4e39e4345084..c33089168880 100644 --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -570,10 +570,6 @@ static int smsc95xx_link_reset(struct usbnet *dev) unsigned long flags; int ret;
- ret = smsc95xx_write_reg(dev, INT_STS, INT_STS_CLEAR_ALL_); - if (ret < 0) - return ret; - spin_lock_irqsave(&pdata->mac_cr_lock, flags); if (pdata->phydev->duplex != DUPLEX_FULL) { pdata->mac_cr &= ~MAC_CR_FDPX_;