From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	Klaus Kudielka <klaus.kudielka@gmail.com>,
	Damien Le Moal <dlemoal@kernel.org>,
	Josua Mayer <josua@solid-run.com>,
	Niklas Cassel <cassel@kernel.org>
Subject: [PATCH 6.1 476/609] ata: libahci_platform: Do not set mask_port_map when not needed
Date: Mon, 17 Aug 2026 15:32:52 +0200
Message-ID: <20260817132559.885094025@linuxfoundation.org>
In-Reply-To: <20260817132543.039278408@linuxfoundation.org>
References: <20260817132543.039278408@linuxfoundation.org>
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6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Damien Le Moal <dlemoal@kernel.org>

commit 2c202e6c4f4dd19d2e8c1dfac9df05170aa3934f upstream.

Commit 8c87215dd3a2 ("ata: libahci_platform: support non-consecutive
port numbers") modified ahci_platform_get_resources() to allow
identifying the ports of a controller that are defined as child nodes of
the controller node in order to support non-consecutive port numbers (as
defined by the platform device tree).

However, this commit also erroneously sets bit 0 of
hpriv->mask_port_map when the platform devices tree does not define port
child nodes, to match the fact that the temporary default number of
ports used in that case is 1 (which is also consistent with the fact
that only index 0 of hpriv->phys[] is initialized with the call to
ahci_platform_get_phy(). But doing so causes ahci_platform_init_host()
to initialize and probe only the first port, even if this function
determines that the controller has in fact multiple ports using the
capability register of the controller (through a call to
ahci_nr_ports()). This can be seen with the ahci_mvebu driver (Armada
385 SoC) with the second port declared as "dummy":

ahci-mvebu f10a8000.sata: masking port_map 0x3 -> 0x1
ahci-mvebu f10a8000.sata: AHCI vers 0001.0000, 32 command slots, 6 Gbps, platform mode
ahci-mvebu f10a8000.sata: 1/2 ports implemented (port mask 0x1)
ahci-mvebu f10a8000.sata: flags: 64bit ncq sntf led only pmp fbs pio slum part sxs
scsi host0: ahci-mvebu
scsi host1: ahci-mvebu
ata1: SATA max UDMA/133 mmio [mem 0xf10a8000-0xf10a9fff] port 0x100 irq 40 lpm-pol 0
ata2: DUMMY

Fix this issue by removing setting bit 0 of hpriv->mask_port_map when
the platform device tree does not define port child nodes.

Reported-by: Klaus Kudielka <klaus.kudielka@gmail.com>
Fixes: 8c87215dd3a2 ("ata: libahci_platform: support non-consecutive port numbers")
Tested-by: Klaus Kudielka <klaus.kudielka@gmail.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Acked-by: Josua Mayer <josua@solid-run.com>
Link: https://lore.kernel.org/r/20250207232915.1439174-1-dlemoal@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/ata/libahci_platform.c |    2 --
 1 file changed, 2 deletions(-)

--- a/drivers/ata/libahci_platform.c
+++ b/drivers/ata/libahci_platform.c
@@ -659,8 +659,6 @@ struct ahci_host_priv *ahci_platform_get
 		 * If no sub-node was found, keep this for device tree
 		 * compatibility
 		 */
-		hpriv->mask_port_map |= BIT(0);
-
 		rc = ahci_platform_get_phy(hpriv, 0, dev, dev->of_node);
 		if (rc)
 			goto err_out;