Re: [PATCH v3] ata: ahci: Skip 200 ms debounce delay for Marvell 88SE9235

[Damien Le Moal <damien.lemoal@opensource.wdc.com>]

On 2/2/22 23:29, Paul Menzel wrote:
> Dear Damien,
> 
> 
> Am 02.02.22 um 09:14 schrieb Damien Le Moal:
>> On 2/1/22 16:12, Paul Menzel wrote:
>>> The 200 ms delay before debouncing the PHY in `sata_link_resume()` is
>>> not needed for the Marvell 88SE9235.
>>>
>>>      $ lspci -nn -s 0021:0e:00.0
>>>      0021:0e:00.0 SATA controller [0106]: Marvell Technology Group Ltd. 88SE9235 PCIe 2.0 x2 4-port SATA 6 Gb/s Controller [1b4b:9235] (rev 11)
>>>
>>> So, remove it. Tested on IBM S822LC with current Linux 5.17-rc1:
>>>
>>> Currently, without this patch (with 200 ms delay), device probe for ata1
>>> takes 485 ms:
>>>
>>>      [    3.358158] ata1: SATA max UDMA/133 abar m2048@0x3fe881000000 port 0x3fe881000100 irq 39
>>>      [    3.358175] ata2: SATA max UDMA/133 abar m2048@0x3fe881000000 port 0x3fe881000180 irq 39
>>>      [    3.358191] ata3: SATA max UDMA/133 abar m2048@0x3fe881000000 port 0x3fe881000200 irq 39
>>>      [    3.358207] ata4: SATA max UDMA/133 abar m2048@0x3fe881000000 port 0x3fe881000280 irq 39
>>>      […]
>>>      [    3.677542] ata3: SATA link down (SStatus 0 SControl 300)
>>>      [    3.677719] ata4: SATA link down (SStatus 0 SControl 300)
>>>      [    3.839242] ata2: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>>>      [    3.839828] ata2.00: ATA-10: ST1000NX0313         00LY266 00LY265IBM, BE33, max UDMA/133
>>>      [    3.840029] ata2.00: 1953525168 sectors, multi 0: LBA48 NCQ (depth 32), AA
>>>      [    3.841796] ata2.00: configured for UDMA/133
>>>      [    3.843231] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>>>      [    3.844083] ata1.00: ATA-10: ST1000NX0313         00LY266 00LY265IBM, BE33, max UDMA/133
>>>      [    3.844313] ata1.00: 1953525168 sectors, multi 0: LBA48 NCQ (depth 32), AA
>>>      [    3.846043] ata1.00: configured for UDMA/133
>>>
>>> With this patch (no delay) device probe for ata1 takes 273 ms:
>>>
>>>      [    3.624259] ata1: SATA max UDMA/133 abar m2048@0x3fe881000000 port 0x3f e881000100 irq 39
>>>      [    3.624436] ata2: SATA max UDMA/133 abar m2048@0x3fe881000000 port 0x3f e881000180 irq 39
>>>      [    3.624452] ata3: SATA max UDMA/133 abar m2048@0x3fe881000000 port 0x3f e881000200 irq 39
>>>      [    3.624468] ata4: SATA max UDMA/133 abar m2048@0x3fe881000000 port 0x3f e881000280 irq 39
>>>      […]
>>>      [    3.731966] ata3: SATA link down (SStatus 0 SControl 300)
>>>      [    3.732069] ata4: SATA link down (SStatus 0 SControl 300)
>>>      [    3.897448] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>>>      [    3.897678] ata2: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>>>      [    3.898140] ata1.00: ATA-10: ST1000NX0313         00LY266 00LY265IBM, BE33, max UDMA/133
>>>      [    3.898175] ata2.00: ATA-10: ST1000NX0313         00LY266 00LY265IBM, BE33, max UDMA/133
>>>      [    3.898287] ata1.00: 1953525168 sectors, multi 0: LBA48 NCQ (depth 32), AA
>>>      [    3.898349] ata2.00: 1953525168 sectors, multi 0: LBA48 NCQ (depth 32), AA
>>>      [    3.900070] ata1.00: configured for UDMA/133
>>>      [    3.900166] ata2.00: configured for UDMA/133
>>>
>>> Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
>>> ---
>>> v2: address comments for commit message (but forgot v2 tag)
>>> v3: resend with v3 tag in subject line/commit message summary
>>>
>>>   drivers/ata/ahci.c | 2 ++
>>>   1 file changed, 2 insertions(+)
>>>
>>> diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
>>> index ab5811ef5a53..edca4e8fd44e 100644
>>> --- a/drivers/ata/ahci.c
>>> +++ b/drivers/ata/ahci.c
>>> @@ -582,6 +582,8 @@ static const struct pci_device_id ahci_pci_tbl[] = {
>>>   	  .driver_data = board_ahci_yes_fbs },
>>>   	{ PCI_DEVICE(PCI_VENDOR_ID_MARVELL_EXT, 0x9230),
>>>   	  .driver_data = board_ahci_yes_fbs },
>>> +	{ PCI_DEVICE(PCI_VENDOR_ID_MARVELL_EXT, 0x9235),
>>> +	  .driver_data = board_ahci_no_debounce_delay },
>>>   	{ PCI_DEVICE(PCI_VENDOR_ID_TTI, 0x0642), /* highpoint rocketraid 642L */
>>>   	  .driver_data = board_ahci_yes_fbs },
>>>   	{ PCI_DEVICE(PCI_VENDOR_ID_TTI, 0x0645), /* highpoint rocketraid 644L */
>>
>> Applied to for-5.18 with commit title and message changes. The title is now:
>>
>> ata: ahci: Add support for Marvell 88SE9235 adapter
>>
>> Since it is exactly what this patch is doing by adding a PCI ID.
> 
> Thank you for applying the patch. I saw the summary/title change also 
> with the other patch. I am sorry, but I totally disagree. Reading that 
> summary/title in `git log --oneline`, it’s not clear at all, what the 
> patch does, and the full description or diff has to be read. “Add 
> support” for me means, that it was unsupported before, which is not true 
> at all as the defaults were used.

Right... I did not consider the final entry in the ahci_pci_tbl table
which matches against the device against the PCI AHCI storage class.
So right you are. I will restore your original commit title/message.

Thanks for checking.

-- 
Damien Le Moal
Western Digital Research