Re: [PATCH] [RESEND] qla2xxx: prevent board_disable from running during EEH

[Himanshu Madhani <himanshu.madhani@qlogic.com>]

On 6/26/15, 9:33 AM, "Mauricio Faria de Oliveira"
<mauricfo@linux.vnet.ibm.com> wrote:

>Commit f3ddac1918fe963bcbf8d407a3a3c0881b47248b ("[SCSI] qla2xxx:
>Disable adapter when we encounter a PCI disconnect.") has introduced a
>code that disables the board, releasing some resources, when reading
>0xffffffff.
>
>In case this happens when there is an EEH, this read will trigger EEH
>detection and set PCI channel offline. EEH will be able to recover the
>card from this state by doing a reset, so it's a better option than
>simply disabling the card.
>
>Since eeh_check_failure will mark the channel as offline before
>returning the read value, in case there really was an EEH, we can simply
>check for pci_channel_offline, preventing the board_disable code from
>running if it's true.
>
>Without this patch, EEH code will try to access those same resources
>that board_disable will try to free. This race can cause EEH recovery to
>fail.
>
>[  504.370577] EEH: Notify device driver to resume
>[  504.370580] qla2xxx [0001:07:00.0]-9002:2: The device failed to
>resume I/O from slot/link_reset.
>
>Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
>Cc: <cascardo@debian.org>
>Cc: <mauricfo@linux.vnet.ibm.com>
>---
>  drivers/scsi/qla2xxx/qla_isr.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/drivers/scsi/qla2xxx/qla_isr.c
>b/drivers/scsi/qla2xxx/qla_isr.c
>index a04a1b1..8132926 100644
>--- a/drivers/scsi/qla2xxx/qla_isr.c
>+++ b/drivers/scsi/qla2xxx/qla_isr.c
>@@ -116,7 +116,7 @@ bool
>  qla2x00_check_reg32_for_disconnect(scsi_qla_host_t *vha, uint32_t reg)
>  {
>  	/* Check for PCI disconnection */
>-	if (reg == 0xffffffff) {
>+	if (reg == 0xffffffff && !pci_channel_offline(vha->hw->pdev)) {
>  		if (!test_and_set_bit(PFLG_DISCONNECTED, &vha->pci_flags) &&
>  		    !test_bit(PFLG_DRIVER_REMOVING, &vha->pci_flags) &&
>  		    !test_bit(PFLG_DRIVER_PROBING, &vha->pci_flags)) {
>-- 
>1.7.10.4
>
>

Looks good. 

Acked-by: Himanshu Madhani <himanshu.madhani@qlogic.com>

>
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