diff mbox series

[net-next,2/7] usbnet: smsc95xx: Don't clear read-only PHY interrupt

Message ID 91a3499156cff9123ede28c95e802d47f4151141.1651037513.git.lukas@wunner.de (mailing list archive)
State Superseded
Headers show
Series Polling be gone on LAN95xx | expand

Commit Message

Lukas Wunner April 27, 2022, 5:48 a.m. UTC
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.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
---
 drivers/net/usb/smsc95xx.c | 4 ----
 1 file changed, 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
index edf0492ad489..2cb44d65bbc3 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_;