diff mbox series

[PATCHv2,net-next,7/7] net: ag71xx: disable napi interrupts during probe

Message ID 20240905194938.8453-8-rosenp@gmail.com (mailing list archive)
State Accepted
Commit 8410adf2e38ad32f20edf6d90e049a8203f51d9e
Delegated to: Netdev Maintainers
Headers show
Series various cleanups | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 16 this patch: 16
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 1 maintainers not CCed: chris.snook@gmail.com
netdev/build_clang success Errors and warnings before: 16 this patch: 16
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 16 this patch: 16
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 12 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Rosen Penev Sept. 5, 2024, 7:49 p.m. UTC 
From: Sven Eckelmann <sven@narfation.org>

ag71xx_probe is registering ag71xx_interrupt as handler for gmac0/gmac1
interrupts. The handler is trying to use napi_schedule to handle the
processing of packets. But the netif_napi_add for this device is
called a lot later in ag71xx_probe.

It can therefore happen that a still running gmac0/gmac1 is triggering the
interrupt handler with a bit from AG71XX_INT_POLL set in
AG71XX_REG_INT_STATUS. The handler will then call napi_schedule and the
napi code will crash the system because the ag->napi is not yet
initialized.

The gmcc0/gmac1 must be brought in a state in which it doesn't signal a
AG71XX_INT_POLL related status bits as interrupt before registering the
interrupt handler. ag71xx_hw_start will take care of re-initializing the
AG71XX_REG_INT_ENABLE.

This will become relevant when dual GMAC devices get added here.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/net/ethernet/atheros/ag71xx.c | 6 ++++++
 1 file changed, 6 insertions(+)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/atheros/ag71xx.c b/drivers/net/ethernet/atheros/ag71xx.c
index e28a4b018b11..96a6189cc31e 100644
--- a/drivers/net/ethernet/atheros/ag71xx.c
+++ b/drivers/net/ethernet/atheros/ag71xx.c
@@ -1850,6 +1850,12 @@  static int ag71xx_probe(struct platform_device *pdev)
 	if (!ag->mac_base)
 		return -ENOMEM;
 
+	/* ensure that HW is in manual polling mode before interrupts are
+	 * activated. Otherwise ag71xx_interrupt might call napi_schedule
+	 * before it is initialized by netif_napi_add.
+	 */
+	ag71xx_int_disable(ag, AG71XX_INT_POLL);
+
 	ndev->irq = platform_get_irq(pdev, 0);
 	err = devm_request_irq(&pdev->dev, ndev->irq, ag71xx_interrupt,
 			       0x0, dev_name(&pdev->dev), ndev);