From 93307b4f8595c9ffb5d35b60c10d7bd85bbc7ffc Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Thu, 12 May 2022 10:42:02 +0200 Subject: [PATCH] usbnet: smsc95xx: Don't clear read-only PHY interrupt 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/DataSheets/LAN950x-Data-Sheet-DS00001875D.pdf Consequently, writing "all ones" to the Interrupt Status Register is pointless and can be dropped. Tested-by: Oleksij Rempel # LAN9514/9512/9500 Tested-by: Ferry Toth # LAN9514 Signed-off-by: Lukas Wunner Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- 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 edf0492ad489a..2cb44d65bbc3c 100644 --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -572,10 +572,6 @@ 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_; -- 2.39.5