Hi! > From: sunghwan jung <onenowy@xxxxxxxxx> > > [ 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", -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
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