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Message-ID: <d10350d1-11e6-497f-9e81-d484bc0aece1@kernel.org>
Date: Thu, 8 Feb 2024 16:44:51 +0900
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Subject: Re: [PATCH] ahci: asm1064: correct count of reported ports
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To: Andrey Melnikov <temnota.am@gmail.com>,
 Hans de Goede <hdegoede@redhat.com>
Cc: linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org
References: <vbpzr7uqpfemb3qa6xy2fxioct44l5vugg2wkywyolfpzqcmau@jgrrhmk2scaj>
 <31d9b48d-320b-44b6-9ab5-d53f741dcc72@redhat.com>
 <CA+PODjozWG6iXcR01KE4N1DyTKeKXtravwanWS3Gtq8mEqutuA@mail.gmail.com>
From: Damien Le Moal <dlemoal@kernel.org>
Organization: Western Digital Research
In-Reply-To: <CA+PODjozWG6iXcR01KE4N1DyTKeKXtravwanWS3Gtq8mEqutuA@mail.gmail.com>
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On 2/8/24 16:21, Andrey Melnikov wrote:
>>
>> Hi Andrey
>>
>> On 2/7/24 10:58, Andrey Jr. Melnikov wrote:
>>> The ASM1064 SATA host controller always reports wrongly,
>>> that it has 24 ports. But in reality, it only has four ports.
>>>
>>> before:
>>> ahci 0000:04:00.0: SSS flag set, parallel bus scan disabled
>>> ahci 0000:04:00.0: AHCI 0001.0301 32 slots 24 ports 6 Gbps 0xffff0f impl SATA mode
>>> ahci 0000:04:00.0: flags: 64bit ncq sntf stag pm led only pio sxs deso sadm sds apst
>>>
>>> after:
>>> ahci 0000:04:00.0: ASM1064 has only four ports
>>> ahci 0000:04:00.0: forcing port_map 0xffff0f -> 0xf
>>> ahci 0000:04:00.0: SSS flag set, parallel bus scan disabled
>>> ahci 0000:04:00.0: AHCI 0001.0301 32 slots 24 ports 6 Gbps 0xf impl SATA mode
>>
>> This still says 24 ports, is that a copy & paste error in the commit msg ?
> 
> This is the raw value of the read-only Host Capability register, how
> should it be changed here? If silicon lies about its configuration -
> kerel prints what it sees from silicon.

This should print the actual number of ports that you forced with the port map
change:

diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 1a63200ea437..7cb3f137bc1b 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -2637,7 +2637,7 @@ void ahci_print_info(struct ata_host *host, const char *scc_s)
                vers & 0xff,

                ((cap >> 8) & 0x1f) + 1,
-               (cap & 0x1f) + 1,
+               (cap & hpriv->saved_port_map) + 1,
                speed_s,
                impl,
                scc_s);


-- 
Damien Le Moal
Western Digital Research