Re: [PATCH v6 04/11] ata: libata: Print quirks applied to devices

[Damien Le Moal <dlemoal@kernel.org>]

On 8/1/24 6:07 PM, Geert Uytterhoeven wrote:
> Hi Damien,
> 
> On Wed, Jul 31, 2024 at 11:08 AM Damien Le Moal <dlemoal@kernel.org> wrote:
>> On 7/31/24 16:27, Geert Uytterhoeven wrote:
>>> On Wed, Jul 31, 2024 at 1:39 AM Damien Le Moal <dlemoal@kernel.org> wrote:
>>>> On 7/30/24 19:09, Geert Uytterhoeven wrote:
>>>>> On Fri, 26 Jul 2024, Damien Le Moal wrote:
>>>>>> Introduce the function ata_dev_print_quirks() to print the quirk flags
>>>>>> that will be applied to a scanned device. This new function is called
>>>>>> from ata_dev_quirks() when a match on a device model or device model
>>>>>> and revision is found for a device in the __ata_dev_quirks array.
>>>>>>
>>>>>> To implement this function, the ATA_QUIRK_ flags are redefined using
>>>>>> the new enum ata_quirk which defines the bit shift for each quirk
>>>>>> flag. The array of strings ata_quirk_names is used to define the name
>>>>>> of each flag, which are printed by ata_dev_print_quirks().
>>>>>>
>>>>>> Example output for a device listed in the __ata_dev_quirks array and
>>>>>> which has the ATA_QUIRK_DISABLE flag applied:
>>>>>>
>>>>>> [10193.461270] ata1: SATA link up 6.0 Gbps (SStatus 133 SControl 300)
>>>>>> [10193.469190] ata1.00: Model 'ASMT109x- Config', rev '2143 5', applying quirks: disable
>>>>>> [10193.469195] ata1.00: unsupported device, disabling
>>>>>> [10193.481564] ata1.00: disable device
>>>>>>
>>>>>> enum ata_quirk also defines the __ATA_QUIRK_MAX value as one plus the
>>>>>> last quirk flag defined. This value is used in ata_dev_quirks() to add a
>>>>>> build time check that all quirk flags fit within the unsigned int
>>>>>> (32-bits) quirks field of struct ata_device.
>>>>>>
>>>>>> Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
>>>>>> Reviewed-by: Igor Pylypiv <ipylypiv@google.com>
>>>>>
>>>>> Thanks for your patch, which is now commit 58157d607aecb4e0 ("ata:
>>>>> libata: Print quirks applied to devices") in libata/for-next.
>>>>>
>>>>> During boot-up on Salvator-XS (using rcar-sata), the quirk info is
>>>>> printed not once, but four times.  Is that intentional?
>>>>
>>>> Not at all. I tested on x86 with AHCI and see this message only once. So it
>>>> could be that different drivers may need some tweaks to avoid this spamming.
>>>> Though it is strange that the initialization or resume path takes this path 4
>>>> times, meaning that the quirks are applied 4 times. Need to look into that.
>>>> What is the driver for rcar-sata ? Compatible string for it would be fine.
>>>
>>> drivers/ata/sata_rcar.c, using renesas,rcar-gen3-sata.
>>>
>>> I added a WARN() to ata_dev_quirks() to show backtraces:
>>>
>>> Call trace:
>>>  ata_dev_quirks+0x98/0x19c
>>>  ata_dev_configure+0x74/0x12d8
>>>  ata_eh_recover+0x8d8/0xd08
>>>  ata_do_eh+0x50/0xa8
>>>  ata_sff_error_handler+0xd0/0xec
>>>  ata_bmdma_error_handler+0x7c/0x12c
>>>  ata_scsi_port_error_handler+0xc8/0x5f8
>>>  ata_scsi_error+0x90/0xcc
>>>  scsi_error_handler+0x148/0x308
>>>  kthread+0xe4/0xf4
>>>  ret_from_fork+0x10/0x20
>>
>> OK. So it is ata_dev_configure() being called many times from EH. Weird.
>> But I have not a lot of experience with the bmdma drivers.
>> Need to look into that.
>>
>> In the meantime, can you try this ?
>>
>> --- a/drivers/ata/libata-core.c
>> +++ b/drivers/ata/libata-core.c
> 
>> @@ -4087,7 +4087,7 @@ static void ata_dev_print_quirks(const struct ata_device *dev,
>>         size_t sz;
>>         char *str;
>>
>> -       if (!quirks)
>> +       if (!ata_dev_print_info(dev) || !quirks)
>>                 return;
>>
>>         sz = 64 + ARRAY_SIZE(ata_quirk_names) * 16;
> 
> Thanks, that reduces the number of quirk prints from 4 to 2 during
> boot-up, and from 4 to 0 when resuming from s2idle/s2ram.

2 times on boot... Hmm.. So that means that you are seeing all the probe
messages twice (and not just the quirk message), right ?

Note that I prepared a better patch for this:

commit bc021024de6034a31a818103e4a9845390ba0c47
Author: Damien Le Moal <dlemoal@kernel.org>
Date:   Thu Aug 1 18:04:22 2024 +0900

    ata: libata: Print device quirks only once

    In ata_dev_print_quirks(), return early if ata_dev_print_info() returns
    false to avoid printing a device quirks multiple times (that is, each
    time ata_dev_revalidate() is called).

    Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
    Fixes: 58157d607aec ("ata: libata: Print quirks applied to devices")
    Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index b4fdb78579c8..3fc9a68d4f45 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -160,7 +160,7 @@ MODULE_DESCRIPTION("Library module for ATA devices");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(DRV_VERSION);

-static inline bool ata_dev_print_info(struct ata_device *dev)
+static inline bool ata_dev_print_info(const struct ata_device *dev)
 {
        struct ata_eh_context *ehc = &dev->link->eh_context;

@@ -4029,7 +4029,7 @@ static void ata_dev_print_quirks(const struct ata_device
*dev,
        size_t sz;
        char *str;

-       if (!quirks)
+       if (!ata_dev_print_info(dev) || !quirks)
                return;

        sz = 64 + ARRAY_SIZE(ata_quirk_names) * 16;

But if you prefer to see the quirk message only once, then I will need to
change this and use a flag to remember that quirk info has been printed
already. But in your case, I suspect you see all probe messages twice, no ?


-- 
Damien Le Moal
Western Digital Research