Messages in this thread | | | Date | Tue, 26 Feb 2008 11:28:23 -0500 | From | Jeff Garzik <> | Subject | Re: [PATCH] sata_nv: fix nmi intr or system hanging in rhel4u6 adma. |
| |
Robert Hancock wrote: > > > Kuan Luo wrote: >> Hi, robert >> One customer reported that their system received a nmi interrupt after >> issuing "dd if=/dev/sdb of=/dev/null" on a defective disk in rhel4u6. >> I tested it and found that my system hung both in rhel4u6(2.6.9-67) and >> 2.6.24-rc7. >> The patch can work well, but I am not sure if the patch has other >> potential effect on adma. >> I attached a file in case of lines breaked. >> >> The below info comes from Gunther Mayer to reproduce the issue. >> " >> used a Seagate ST3500841NS 3.AE for my test; probably other seagate >> drives are also capable of creating media errors with the new hdparm-8.1: >> - compile hdparm-8.1 - hdparm -- yes-i-know-what-i-am-doing >> --make-bad-sector 60000 /dev/sdb >> Unfortunately this does not succeed for nvidia sata controller (timeouts >> et al.), but it worked fine on AHCI machine (e.g. FSC R640). >> When I insert this newly created defective disk in Ultra 20, it >> reboots within seconds after issueing "dd if=/dev/sdb of=/dev/null". " >> >> Signed-off-by: kluo@nvidia.com >> >> --- >> >> drivers/ata/sata_nv.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/ata/sata_nv.c b/drivers/ata/sata_nv.c >> index ed5473b..e824260 100644 >> --- a/drivers/ata/sata_nv.c >> +++ b/drivers/ata/sata_nv.c >> @@ -837,9 +837,10 @@ static void nv_adma_tf_read(struct ata_port *ap, >> struct ata_taskfile *tf) >> all shortly be aborted anyway. We assume that NCQ commands >> are not >> issued via passthrough, which is the only way that switching >> into >> ADMA mode could abort outstanding commands. */ >> - nv_adma_register_mode(ap); >> + struct nv_adma_port_priv *pp = ap->private_data; >> >> - ata_tf_read(ap, tf); >> + if (pp->flags & NV_ADMA_PORT_REGISTER_MODE) >> + ata_tf_read(ap, tf); >> } >> >> static unsigned int nv_adma_tf_to_cpb(struct ata_taskfile *tf, __le16 >> *cpb) > > This is basically avoiding switching into register mode, right? I don't > think this is a very good solution as the point of the tf_read function > is that it's supposed to read the taskfile provided by the drive to > diagnose the error, so not doing this isn't a good thing.
Agree with this analysis -- if ->tf_read() is being called, then obviously the core wants a current copy of the device's ATA registers.
It is not a good solution to simply avoiding returning meaningful data, because -- as Robert notes -- we need tf_read for analysis.
Jeff
| |