From 9c72ebef5aabf3532469d602a9d87beceea268b1 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Fri, 26 Jun 2009 11:22:37 -0700 Subject: [PATCH] ide-cd: handle fragmented packet commands gracefully There are some devices in the wild that clear the DRQ bit during the last word of a packet command and therefore could use a "second chance" for that last word of data to be xferred instead of simply failing the request. Do that by attempting to suck in those last bytes in PIO mode. In addition, the ATA_ERR bit has to be cleared for we cannot be sure the data is valid otherwise. See http://bugzilla.kernel.org/show_bug.cgi?id=13399 for details. Signed-off-by: Borislav Petkov Acked-by: Bartlomiej Zolnierkiewicz Signed-off-by: David S. Miller --- drivers/ide/ide-cd.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c index f0ede5953af8..6a9a769bffc1 100644 --- a/drivers/ide/ide-cd.c +++ b/drivers/ide/ide-cd.c @@ -592,9 +592,19 @@ static ide_startstop_t cdrom_newpc_intr(ide_drive_t *drive) } } else if (!blk_pc_request(rq)) { ide_cd_request_sense_fixup(drive, cmd); - /* complain if we still have data left to transfer */ + uptodate = cmd->nleft ? 0 : 1; - if (uptodate == 0) + + /* + * suck out the remaining bytes from the drive in an + * attempt to complete the data xfer. (see BZ#13399) + */ + if (!(stat & ATA_ERR) && !uptodate && thislen) { + ide_pio_bytes(drive, cmd, write, thislen); + uptodate = cmd->nleft ? 0 : 1; + } + + if (!uptodate) rq->cmd_flags |= REQ_FAILED; } goto out_end;