6.9-stable patches

added patches:
	net-ks8851-fix-another-tx-stall-caused-by-wrong-isr-flag-handling.patch

diff --git a/queue-6.9/net-ks8851-fix-another-tx-stall-caused-by-wrong-isr-flag-handling.patch b/queue-6.9/net-ks8851-fix-another-tx-stall-caused-by-wrong-isr-flag-handling.patch
new file mode 100644 (file)
index 0000000..344d3d4
--- /dev/null
+++ b/queue-6.9/net-ks8851-fix-another-tx-stall-caused-by-wrong-isr-flag-handling.patch
@@ -0,0 +1,108 @@
+From 317a215d493230da361028ea8a4675de334bfa1a Mon Sep 17 00:00:00 2001
+From: Ronald Wahl <ronald.wahl@raritan.com>
+Date: Mon, 13 May 2024 16:39:22 +0200
+Subject: net: ks8851: Fix another TX stall caused by wrong ISR flag handling
+
+From: Ronald Wahl <ronald.wahl@raritan.com>
+
+commit 317a215d493230da361028ea8a4675de334bfa1a upstream.
+
+Under some circumstances it may happen that the ks8851 Ethernet driver
+stops sending data.
+
+Currently the interrupt handler resets the interrupt status flags in the
+hardware after handling TX. With this approach we may lose interrupts in
+the time window between handling the TX interrupt and resetting the TX
+interrupt status bit.
+
+When all of the three following conditions are true then transmitting
+data stops:
+
+  - TX queue is stopped to wait for room in the hardware TX buffer
+  - no queued SKBs in the driver (txq) that wait for being written to hw
+  - hardware TX buffer is empty and the last TX interrupt was lost
+
+This is because reenabling the TX queue happens when handling the TX
+interrupt status but if the TX status bit has already been cleared then
+this interrupt will never come.
+
+With this commit the interrupt status flags will be cleared before they
+are handled. That way we stop losing interrupts.
+
+The wrong handling of the ISR flags was there from the beginning but
+with commit 3dc5d4454545 ("net: ks8851: Fix TX stall caused by TX
+buffer overrun") the issue becomes apparent.
+
+Fixes: 3dc5d4454545 ("net: ks8851: Fix TX stall caused by TX buffer overrun")
+Cc: "David S. Miller" <davem@davemloft.net>
+Cc: Eric Dumazet <edumazet@google.com>
+Cc: Jakub Kicinski <kuba@kernel.org>
+Cc: Paolo Abeni <pabeni@redhat.com>
+Cc: Simon Horman <horms@kernel.org>
+Cc: netdev@vger.kernel.org
+Cc: stable@vger.kernel.org # 5.10+
+Signed-off-by: Ronald Wahl <ronald.wahl@raritan.com>
+Reviewed-by: Simon Horman <horms@kernel.org>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/net/ethernet/micrel/ks8851_common.c |   18 +-----------------
+ 1 file changed, 1 insertion(+), 17 deletions(-)
+
+--- a/drivers/net/ethernet/micrel/ks8851_common.c
++++ b/drivers/net/ethernet/micrel/ks8851_common.c
+@@ -328,7 +328,6 @@ static irqreturn_t ks8851_irq(int irq, v
+ {
+       struct ks8851_net *ks = _ks;
+       struct sk_buff_head rxq;
+-      unsigned handled = 0;
+       unsigned long flags;
+       unsigned int status;
+       struct sk_buff *skb;
+@@ -336,24 +335,17 @@ static irqreturn_t ks8851_irq(int irq, v
+       ks8851_lock(ks, &flags);
+ 
+       status = ks8851_rdreg16(ks, KS_ISR);
++      ks8851_wrreg16(ks, KS_ISR, status);
+ 
+       netif_dbg(ks, intr, ks->netdev,
+                 "%s: status 0x%04x\n", __func__, status);
+ 
+-      if (status & IRQ_LCI)
+-              handled |= IRQ_LCI;
+-
+       if (status & IRQ_LDI) {
+               u16 pmecr = ks8851_rdreg16(ks, KS_PMECR);
+               pmecr &= ~PMECR_WKEVT_MASK;
+               ks8851_wrreg16(ks, KS_PMECR, pmecr | PMECR_WKEVT_LINK);
+-
+-              handled |= IRQ_LDI;
+       }
+ 
+-      if (status & IRQ_RXPSI)
+-              handled |= IRQ_RXPSI;
+-
+       if (status & IRQ_TXI) {
+               unsigned short tx_space = ks8851_rdreg16(ks, KS_TXMIR);
+ 
+@@ -365,20 +357,12 @@ static irqreturn_t ks8851_irq(int irq, v
+               if (netif_queue_stopped(ks->netdev))
+                       netif_wake_queue(ks->netdev);
+               spin_unlock(&ks->statelock);
+-
+-              handled |= IRQ_TXI;
+       }
+ 
+-      if (status & IRQ_RXI)
+-              handled |= IRQ_RXI;
+-
+       if (status & IRQ_SPIBEI) {
+               netdev_err(ks->netdev, "%s: spi bus error\n", __func__);
+-              handled |= IRQ_SPIBEI;
+       }
+ 
+-      ks8851_wrreg16(ks, KS_ISR, handled);
+-
+       if (status & IRQ_RXI) {
+               /* the datasheet says to disable the rx interrupt during
+                * packet read-out, however we're masking the interrupt

diff --git a/queue-6.9/series b/queue-6.9/series
index 811dd41d717f845cbf6ffbbe644e03339107007e..5ebd0a2e7ad11d4be41edd663847bf11b1909681 100644 (file)
--- a/queue-6.9/series
+++ b/queue-6.9/series
@@ -2,3 +2,4 @@ bluetooth-btusb-fix-the-patch-for-mt7920-the-affected-to-mt7921.patch
 wifi-iwlwifi-use-request_module_nowait.patch
 cpufreq-amd-pstate-fix-the-highest-frequency-issue-which-limits-performance.patch
 drm-amd-display-fix-division-by-zero-in-setup_dsc_config.patch
+net-ks8851-fix-another-tx-stall-caused-by-wrong-isr-flag-handling.patch