FAILED: patch "[PATCH] net: ravb: Enforce descriptor type ordering" failed to apply to 5.15-stable tree
The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 5370c31e84b0e0999c7b5ff949f4e104def35584 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025102623-footless-outcast-b793@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 5370c31e84b0e0999c7b5ff949f4e104def35584 Mon Sep 17 00:00:00 2001 From: Lad Prabhakar prabhakar.mahadev-lad.rj@bp.renesas.com Date: Fri, 17 Oct 2025 16:18:29 +0100 Subject: [PATCH] net: ravb: Enforce descriptor type ordering MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
Ensure the TX descriptor type fields are published in a safe order so the DMA engine never begins processing a descriptor chain before all descriptor fields are fully initialised.
For multi-descriptor transmits the driver writes DT_FEND into the last descriptor and DT_FSTART into the first. The DMA engine begins processing when it observes DT_FSTART. Move the dma_wmb() barrier so it executes immediately after DT_FEND and immediately before writing DT_FSTART (and before DT_FSINGLE in the single-descriptor case). This guarantees that all prior CPU writes to the descriptor memory are visible to the device before DT_FSTART is seen.
This avoids a situation where compiler/CPU reordering could publish DT_FSTART ahead of DT_FEND or other descriptor fields, allowing the DMA to start on a partially initialised chain and causing corrupted transmissions or TX timeouts. Such a failure was observed on RZ/G2L with an RT kernel as transmit queue timeouts and device resets.
Fixes: 2f45d1902acf ("ravb: minimize TX data copying") Cc: stable@vger.kernel.org Co-developed-by: Fabrizio Castro fabrizio.castro.jz@renesas.com Signed-off-by: Fabrizio Castro fabrizio.castro.jz@renesas.com Signed-off-by: Lad Prabhakar prabhakar.mahadev-lad.rj@bp.renesas.com Reviewed-by: Niklas Söderlund niklas.soderlund+renesas@ragnatech.se Link: https://patch.msgid.link/20251017151830.171062-4-prabhakar.mahadev-lad.rj@bp... Signed-off-by: Jakub Kicinski kuba@kernel.org
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index 9d3bd65b85ff..044ee83c63bb 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -2211,13 +2211,25 @@ static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev)
skb_tx_timestamp(skb); } - /* Descriptor type must be set after all the above writes */ - dma_wmb(); + if (num_tx_desc > 1) { desc->die_dt = DT_FEND; desc--; + /* When using multi-descriptors, DT_FEND needs to get written + * before DT_FSTART, but the compiler may reorder the memory + * writes in an attempt to optimize the code. + * Use a dma_wmb() barrier to make sure DT_FEND and DT_FSTART + * are written exactly in the order shown in the code. + * This is particularly important for cases where the DMA engine + * is already running when we are running this code. If the DMA + * sees DT_FSTART without the corresponding DT_FEND it will enter + * an error condition. + */ + dma_wmb(); desc->die_dt = DT_FSTART; } else { + /* Descriptor type must be set after all the above writes */ + dma_wmb(); desc->die_dt = DT_FSINGLE; } ravb_modify(ndev, TCCR, TCCR_TSRQ0 << q, TCCR_TSRQ0 << q);
From: Biju Das biju.das.jz@bp.renesas.com
[ Upstream commit 7e09a052dc4e30ce07fd7b3aa58a7d993f73a9d7 ]
R-Car supports gPTP feature whereas RZ/G2L does not support it. This patch excludes gtp feature support for RZ/G2L.
Signed-off-by: Biju Das biju.das.jz@bp.renesas.com Reviewed-by: Lad Prabhakar prabhakar.mahadev-lad.rj@bp.renesas.com Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: 5370c31e84b0 ("net: ravb: Enforce descriptor type ordering") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/renesas/ravb_main.c | 85 ++++++++++++++---------- 1 file changed, 49 insertions(+), 36 deletions(-)
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index eee446e500486..ad61226098973 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -1321,6 +1321,7 @@ static int ravb_get_ts_info(struct net_device *ndev, struct ethtool_ts_info *info) { struct ravb_private *priv = netdev_priv(ndev); + const struct ravb_hw_info *hw_info = priv->info;
info->so_timestamping = SOF_TIMESTAMPING_TX_SOFTWARE | @@ -1334,7 +1335,8 @@ static int ravb_get_ts_info(struct net_device *ndev, (1 << HWTSTAMP_FILTER_NONE) | (1 << HWTSTAMP_FILTER_PTP_V2_L2_EVENT) | (1 << HWTSTAMP_FILTER_ALL); - info->phc_index = ptp_clock_index(priv->ptp.clock); + if (hw_info->gptp || hw_info->ccc_gac) + info->phc_index = ptp_clock_index(priv->ptp.clock);
return 0; } @@ -1565,6 +1567,7 @@ static void ravb_tx_timeout_work(struct work_struct *work) static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev) { struct ravb_private *priv = netdev_priv(ndev); + const struct ravb_hw_info *info = priv->info; unsigned int num_tx_desc = priv->num_tx_desc; u16 q = skb_get_queue_mapping(skb); struct ravb_tstamp_skb *ts_skb; @@ -1641,28 +1644,30 @@ static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev) desc->dptr = cpu_to_le32(dma_addr);
/* TX timestamp required */ - if (q == RAVB_NC) { - ts_skb = kmalloc(sizeof(*ts_skb), GFP_ATOMIC); - if (!ts_skb) { - if (num_tx_desc > 1) { - desc--; - dma_unmap_single(ndev->dev.parent, dma_addr, - len, DMA_TO_DEVICE); + if (info->gptp || info->ccc_gac) { + if (q == RAVB_NC) { + ts_skb = kmalloc(sizeof(*ts_skb), GFP_ATOMIC); + if (!ts_skb) { + if (num_tx_desc > 1) { + desc--; + dma_unmap_single(ndev->dev.parent, dma_addr, + len, DMA_TO_DEVICE); + } + goto unmap; } - goto unmap; + ts_skb->skb = skb_get(skb); + ts_skb->tag = priv->ts_skb_tag++; + priv->ts_skb_tag &= 0x3ff; + list_add_tail(&ts_skb->list, &priv->ts_skb_list); + + /* TAG and timestamp required flag */ + skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS; + desc->tagh_tsr = (ts_skb->tag >> 4) | TX_TSR; + desc->ds_tagl |= cpu_to_le16(ts_skb->tag << 12); } - ts_skb->skb = skb_get(skb); - ts_skb->tag = priv->ts_skb_tag++; - priv->ts_skb_tag &= 0x3ff; - list_add_tail(&ts_skb->list, &priv->ts_skb_list);
- /* TAG and timestamp required flag */ - skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS; - desc->tagh_tsr = (ts_skb->tag >> 4) | TX_TSR; - desc->ds_tagl |= cpu_to_le16(ts_skb->tag << 12); + skb_tx_timestamp(skb); } - - skb_tx_timestamp(skb); /* Descriptor type must be set after all the above writes */ dma_wmb(); if (num_tx_desc > 1) { @@ -1773,10 +1778,12 @@ static int ravb_close(struct net_device *ndev) "device will be stopped after h/w processes are done.\n");
/* Clear the timestamp list */ - list_for_each_entry_safe(ts_skb, ts_skb2, &priv->ts_skb_list, list) { - list_del(&ts_skb->list); - kfree_skb(ts_skb->skb); - kfree(ts_skb); + if (info->gptp || info->ccc_gac) { + list_for_each_entry_safe(ts_skb, ts_skb2, &priv->ts_skb_list, list) { + list_del(&ts_skb->list); + kfree_skb(ts_skb->skb); + kfree(ts_skb); + } }
/* PHY disconnect */ @@ -2108,9 +2115,11 @@ static void ravb_set_config_mode(struct net_device *ndev) ravb_modify(ndev, CCC, CCC_OPC, CCC_OPC_CONFIG); /* Set CSEL value */ ravb_modify(ndev, CCC, CCC_CSEL, CCC_CSEL_HPB); - } else { + } else if (info->ccc_gac) { ravb_modify(ndev, CCC, CCC_OPC, CCC_OPC_CONFIG | CCC_GAC | CCC_CSEL_HPB); + } else { + ravb_modify(ndev, CCC, CCC_OPC, CCC_OPC_CONFIG); } }
@@ -2298,13 +2307,15 @@ static int ravb_probe(struct platform_device *pdev) /* Set AVB config mode */ ravb_set_config_mode(ndev);
- /* Set GTI value */ - error = ravb_set_gti(ndev); - if (error) - goto out_disable_refclk; + if (info->gptp || info->ccc_gac) { + /* Set GTI value */ + error = ravb_set_gti(ndev); + if (error) + goto out_disable_refclk;
- /* Request GTI loading */ - ravb_modify(ndev, GCCR, GCCR_LTI, GCCR_LTI); + /* Request GTI loading */ + ravb_modify(ndev, GCCR, GCCR_LTI, GCCR_LTI); + }
if (info->internal_delay) { ravb_parse_delay_mode(np, ndev); @@ -2501,13 +2512,15 @@ static int __maybe_unused ravb_resume(struct device *dev) /* Set AVB config mode */ ravb_set_config_mode(ndev);
- /* Set GTI value */ - ret = ravb_set_gti(ndev); - if (ret) - return ret; + if (info->gptp || info->ccc_gac) { + /* Set GTI value */ + ret = ravb_set_gti(ndev); + if (ret) + return ret;
- /* Request GTI loading */ - ravb_modify(ndev, GCCR, GCCR_LTI, GCCR_LTI); + /* Request GTI loading */ + ravb_modify(ndev, GCCR, GCCR_LTI, GCCR_LTI); + }
if (info->internal_delay) ravb_set_delay_mode(ndev);
From: Lad Prabhakar prabhakar.mahadev-lad.rj@bp.renesas.com
[ Upstream commit 5370c31e84b0e0999c7b5ff949f4e104def35584 ]
Ensure the TX descriptor type fields are published in a safe order so the DMA engine never begins processing a descriptor chain before all descriptor fields are fully initialised.
For multi-descriptor transmits the driver writes DT_FEND into the last descriptor and DT_FSTART into the first. The DMA engine begins processing when it observes DT_FSTART. Move the dma_wmb() barrier so it executes immediately after DT_FEND and immediately before writing DT_FSTART (and before DT_FSINGLE in the single-descriptor case). This guarantees that all prior CPU writes to the descriptor memory are visible to the device before DT_FSTART is seen.
This avoids a situation where compiler/CPU reordering could publish DT_FSTART ahead of DT_FEND or other descriptor fields, allowing the DMA to start on a partially initialised chain and causing corrupted transmissions or TX timeouts. Such a failure was observed on RZ/G2L with an RT kernel as transmit queue timeouts and device resets.
Fixes: 2f45d1902acf ("ravb: minimize TX data copying") Cc: stable@vger.kernel.org Co-developed-by: Fabrizio Castro fabrizio.castro.jz@renesas.com Signed-off-by: Fabrizio Castro fabrizio.castro.jz@renesas.com Signed-off-by: Lad Prabhakar prabhakar.mahadev-lad.rj@bp.renesas.com Reviewed-by: Niklas Söderlund niklas.soderlund+renesas@ragnatech.se Link: https://patch.msgid.link/20251017151830.171062-4-prabhakar.mahadev-lad.rj@bp... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/renesas/ravb_main.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index ad61226098973..5ceab1457108f 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -1668,13 +1668,25 @@ static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev)
skb_tx_timestamp(skb); } - /* Descriptor type must be set after all the above writes */ - dma_wmb(); + if (num_tx_desc > 1) { desc->die_dt = DT_FEND; desc--; + /* When using multi-descriptors, DT_FEND needs to get written + * before DT_FSTART, but the compiler may reorder the memory + * writes in an attempt to optimize the code. + * Use a dma_wmb() barrier to make sure DT_FEND and DT_FSTART + * are written exactly in the order shown in the code. + * This is particularly important for cases where the DMA engine + * is already running when we are running this code. If the DMA + * sees DT_FSTART without the corresponding DT_FEND it will enter + * an error condition. + */ + dma_wmb(); desc->die_dt = DT_FSTART; } else { + /* Descriptor type must be set after all the above writes */ + dma_wmb(); desc->die_dt = DT_FSINGLE; } ravb_modify(ndev, TCCR, TCCR_TSRQ0 << q, TCCR_TSRQ0 << q);
linux-stable-mirror@lists.linaro.org
-
gregkh＠linuxfoundation.org -
Sasha Levin