FAILED: Patch "net: stmmac: dwmac-loongson: Set clk_csr_i to 100-150MHz" failed to apply to 5.15-stable tree

FAILED: Patch "net: stmmac: dwmac-loongson: Set clk_csr_i to 100-150MHz" failed to apply to 5.15-stable tree

[Sasha Levin]

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>.

Thanks,
Sasha

------------------ original commit in Linus's tree ------------------

From e1aa5ef892fb4fa9014a25e87b64b97347919d37 Mon Sep 17 00:00:00 2001
From: Huacai Chen <chenhuacai@loongson.cn>
Date: Tue, 3 Feb 2026 14:29:01 +0800
Subject: [PATCH] net: stmmac: dwmac-loongson: Set clk_csr_i to 100-150MHz

Current clk_csr_i setting of Loongson STMMAC (including LS7A1000/2000
and LS2K1000/2000/3000) are copy & paste from other drivers. In fact,
Loongson STMMAC use 125MHz clocks and need 62 freq division to within
2.5MHz, meeting most PHY MDC requirement. So fix by setting clk_csr_i
to 100-150MHz, otherwise some PHYs may link fail.

Cc: stable@vger.kernel.org
Fixes: 30bba69d7db40e7 ("stmmac: pci: Add dwmac support for Loongson")
Signed-off-by: Hongliang Wang <wanghongliang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Link: https://patch.msgid.link/20260203062901.2158236-1-chenhuacai@loongson.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
index 107a7c84ace80..c05e3e7a539cf 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
@@ -91,8 +91,8 @@ static void loongson_default_data(struct pci_dev *pdev,
 	/* Get bus_id, this can be overwritten later */
 	plat->bus_id = pci_dev_id(pdev);
 
-	/* clk_csr_i = 20-35MHz & MDC = clk_csr_i/16 */
-	plat->clk_csr = STMMAC_CSR_20_35M;
+	/* clk_csr_i = 100-150MHz & MDC = clk_csr_i/62 */
+	plat->clk_csr = STMMAC_CSR_100_150M;
 	plat->core_type = DWMAC_CORE_GMAC;
 	plat->force_sf_dma_mode = 1;
 
-- 
2.51.0

Re: FAILED: Patch "net: stmmac: dwmac-loongson: Set clk_csr_i to 100-150MHz" failed to apply to 5.15-stable tree

[Huacai Chen]

Hi, Sasha,

On Sun, Mar 1, 2026 at 9:53 AM Sasha Levin <sashal@kernel.org> wrote:
>
> 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>.
I have already submit a patch for 5.15 some days ago:
https://lore.kernel.org/loongarch/20260218121310.2545149-1-chenhuacai@loongson.cn/T/#u

Huacai
>
> Thanks,
> Sasha
>
> ------------------ original commit in Linus's tree ------------------
>
> From e1aa5ef892fb4fa9014a25e87b64b97347919d37 Mon Sep 17 00:00:00 2001
> From: Huacai Chen <chenhuacai@loongson.cn>
> Date: Tue, 3 Feb 2026 14:29:01 +0800
> Subject: [PATCH] net: stmmac: dwmac-loongson: Set clk_csr_i to 100-150MHz
>
> Current clk_csr_i setting of Loongson STMMAC (including LS7A1000/2000
> and LS2K1000/2000/3000) are copy & paste from other drivers. In fact,
> Loongson STMMAC use 125MHz clocks and need 62 freq division to within
> 2.5MHz, meeting most PHY MDC requirement. So fix by setting clk_csr_i
> to 100-150MHz, otherwise some PHYs may link fail.
>
> Cc: stable@vger.kernel.org
> Fixes: 30bba69d7db40e7 ("stmmac: pci: Add dwmac support for Loongson")
> Signed-off-by: Hongliang Wang <wanghongliang@loongson.cn>
> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
> Link: https://patch.msgid.link/20260203062901.2158236-1-chenhuacai@loongson.cn
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> ---
>  drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
> index 107a7c84ace80..c05e3e7a539cf 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
> @@ -91,8 +91,8 @@ static void loongson_default_data(struct pci_dev *pdev,
>         /* Get bus_id, this can be overwritten later */
>         plat->bus_id = pci_dev_id(pdev);
>
> -       /* clk_csr_i = 20-35MHz & MDC = clk_csr_i/16 */
> -       plat->clk_csr = STMMAC_CSR_20_35M;
> +       /* clk_csr_i = 100-150MHz & MDC = clk_csr_i/62 */
> +       plat->clk_csr = STMMAC_CSR_100_150M;
>         plat->core_type = DWMAC_CORE_GMAC;
>         plat->force_sf_dma_mode = 1;
>
> --
> 2.51.0
>
>
>
>