Hi!
From: sunghwan jung onenowy@gmail.com
[ Upstream commit ad5dbfc123e6ffbbde194e2a4603323e09f741ee ]
This reverts commit 86d92f5465958752481269348d474414dccb1552, which fix the timeout issue for "Samsung Fit Flash".
But the commit affects not only "Samsung Fit Flash" but also other usb storages that use the same controller and causes severe performance regression.
# hdparm -t /dev/sda (without the quirk) Timing buffered disk reads: 622 MB in 3.01 seconds = 206.66 MB/sec
# hdparm -t /dev/sda (with the quirk) Timing buffered disk reads: 220 MB in 3.00 seconds = 73.32 MB/sec
The commit author mentioned that "Issue was reproduced after device has bad block", so this quirk should be applied when we have the timeout issue with a device that has bad blocks.
We revert the commit so that we apply this quirk by adding kernel paramters using a bootloader or other ways when we really need it, without the performance regression with devices that don't have the issue.
Re-introducing timeouts for users in middle of stable series... may not be nice. Is there better fix in a follow up to this that was not backported?
I see that buffered reads got faster, but that may not really mean real performance gains...
Best regards, Pavel
drivers/usb/storage/unusual_devs.h | 6 ------ 1 file changed, 6 deletions(-)
diff --git a/drivers/usb/storage/unusual_devs.h b/drivers/usb/storage/unusual_devs.h index 5a6ca1460711..8c51bb66f16f 100644 --- a/drivers/usb/storage/unusual_devs.h +++ b/drivers/usb/storage/unusual_devs.h @@ -1294,12 +1294,6 @@ UNUSUAL_DEV( 0x090a, 0x1200, 0x0000, 0x9999, USB_SC_RBC, USB_PR_BULK, NULL, 0 ), -UNUSUAL_DEV(0x090c, 0x1000, 0x1100, 0x1100,
"Samsung","Flash Drive FIT",USB_SC_DEVICE, USB_PR_DEVICE, NULL,US_FL_MAX_SECTORS_64),/* aeb */ UNUSUAL_DEV( 0x090c, 0x1132, 0x0000, 0xffff, "Feiya",