[PATCH net-next v3 03/12] net: ethernet: cortina: Drain free queue IRQ before resize
flat view
COOLING14d
SUPERSEDED
From: Linus Walleij <linusw@kernel.org>
Date: 2026-10-02 16:24:54
Subsystem:
arm/cortina systems gemini arm architecture, networking drivers, the rest · Maintainers:
Hans Ulli Kroll, Linus Walleij, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Revision v3 of 4 in this series.
Revisions (4)
- v2 [diff vs current]
- v3 current
- v4 [diff vs current]
- v5 [diff vs current]
The software free queue interrupt remains registered while both netdevs
are down. Merely masking the device source does not stop a threaded
handler which was already woken. That handler can refill the queue while
resize frees its ring and page metadata, or re-enable the source after
teardown.
The free queue interrupt is routed through port 1. Disable that Linux IRQ
for the entire resize. disable_irq() drains hard and threaded handlers and
prevents a new thread from being woken.
After the drain, mask the device source and rebuild the queue. If setup
succeeds, re-enable the source before the Linux IRQ. On failure, keep the
source masked, clear freed queue state and restore the Linux IRQ so a later
open retries setup safely.
Fixes: 4d5ae32f5e1e ("net: ethernet: Add a driver for Gemini gigabit ethernet")
Assisted-by: LLM
Signed-off-by: Linus Walleij <linusw@kernel.org>
---
drivers/net/ethernet/cortina/gemini.c | 40 +++++++++++++++++++++++------------
1 file changed, 26 insertions(+), 14 deletions(-)
diff --git a/drivers/net/ethernet/cortina/gemini.c b/drivers/net/ethernet/cortina/gemini.c
index 15ad9f721dd5..a2daf22e7698 100644
--- a/drivers/net/ethernet/cortina/gemini.c
+++ b/drivers/net/ethernet/cortina/gemini.c@@ -984,6 +984,8 @@ static int geth_setup_freeq(struct gemini_ethernet *geth) } kfree(geth->freeq_pages); + geth->freeq_pages = NULL; + geth->num_freeq_pages = 0; err_freeq: dma_free_coherent(geth->dev, sizeof(*geth->freeq_ring) << geth->freeq_order,
@@ -1024,10 +1026,28 @@ static void geth_cleanup_freeq(struct gemini_ethernet *geth) } kfree(geth->freeq_pages); + geth->freeq_pages = NULL; + geth->num_freeq_pages = 0; dma_free_coherent(geth->dev, sizeof(*geth->freeq_ring) << geth->freeq_order, geth->freeq_ring, geth->freeq_dma_base); + geth->freeq_ring = NULL; +} + +static void geth_set_freeq_irq(struct gemini_ethernet *geth, bool enable) +{ + unsigned long flags; + u32 val; + + spin_lock_irqsave(&geth->irq_lock, flags); + val = readl(geth->base + GLOBAL_INTERRUPT_ENABLE_4_REG); + if (enable) + val |= SWFQ_EMPTY_INT_BIT; + else + val &= ~SWFQ_EMPTY_INT_BIT; + writel(val, geth->base + GLOBAL_INTERRUPT_ENABLE_4_REG); + spin_unlock_irqrestore(&geth->irq_lock, flags); } /**
@@ -1047,8 +1067,6 @@ static int geth_resize_freeq(struct gemini_ethernet_port *port) struct net_device *other_netdev; unsigned int new_size = 0; unsigned int new_order; - unsigned long flags; - u32 en; int ret; /* The software free queue interrupt is routed through port 1. */
@@ -1080,16 +1098,11 @@ static int geth_resize_freeq(struct gemini_ethernet_port *port) new_order = min(15, ilog2(new_size - 1) + 1); dev_dbg(geth->dev, "set shared queue to size %d order %d\n", new_size, new_order); - if (geth->freeq_order == new_order) + if (geth->freeq_ring && geth->freeq_order == new_order) return 0; - spin_lock_irqsave(&geth->irq_lock, flags); - - /* Disable the software queue IRQs */ - en = readl(geth->base + GLOBAL_INTERRUPT_ENABLE_4_REG); - en &= ~SWFQ_EMPTY_INT_BIT; - writel(en, geth->base + GLOBAL_INTERRUPT_ENABLE_4_REG); - spin_unlock_irqrestore(&geth->irq_lock, flags); + disable_irq(geth->port1->irq); + geth_set_freeq_irq(geth, false); /* Drop the old queue */ if (geth->freeq_ring)
@@ -1103,10 +1116,9 @@ static int geth_resize_freeq(struct gemini_ethernet_port *port) * after probe(), this is where the interrupts get turned on * in the first place. */ - spin_lock_irqsave(&geth->irq_lock, flags); - en |= SWFQ_EMPTY_INT_BIT; - writel(en, geth->base + GLOBAL_INTERRUPT_ENABLE_4_REG); - spin_unlock_irqrestore(&geth->irq_lock, flags); + if (!ret) + geth_set_freeq_irq(geth, true); + enable_irq(geth->port1->irq); return ret; }
--
2.55.0