Re: [PATCH] libata: Use per port sync for detach

[John Garry]

On 15/05/2020 18:48, Kai-Heng Feng wrote:

841]  ret_from_fork+0x10/0x1c
[   28.393400] ---[ end trace 9972785c7052048f ]---
[   28.435826] ahci 0000:b4:03.0: SSS flag set, parallel bus scan disabled

Can you please test the following patch:

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 474c6c34fe02..51ee0cc4d414 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -3583,8 +3583,10 @@ int ata_eh_recover(struct ata_port *ap, 
ata_prereset_fn_t prereset,
         rc = 0;

/* if UNLOADING, finish immediately */

-       if (ap->pflags & ATA_PFLAG_UNLOADING)
+       if (ap->pflags & ATA_PFLAG_UNLOADING) {
+               ap->pflags |= ATA_PFLAG_UNLOADED;
                 goto out;
+       }

It's only compile-tested, many drivers panic with 
CONFIG_DEBUG_TEST_DRIVER_REMOVE enabled, so the system I have can't even boot 
properly:(

ok, let me debug this today.

Thanks,
John