diff options
| author | Paul Gortmaker <paul.gortmaker@windriver.com> | 2013-02-04 09:49:42 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-02-04 21:08:01 -0500 |
| commit | 7c1e7e99ab8fac65222cfc0a2cc35f3678086cfa (patch) | |
| tree | b44a099570301072075c56bca58ee68f9fb613d8 | |
| parent | 27000929ef0f137b34ba219eb04b05e772eff2b1 (diff) | |
gianfar: dont conditionally alloc Rx/Err irq structs
Commit ee873fda3bec7c668407b837fc5519eb961fcd37
"gianfar: Pack struct gfar_priv_grp into three cachelines"
causes the following null dereference at driver init on sbc8548:
libphy: Freescale PowerQUICC MII Bus: probed
Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xc01d6a38
Oops: Kernel access of bad area, sig: 11 [#1]
[...]
NIP [c01d6a38] gfar_parse_group+0x228/0x280
LR [c01d6a34] gfar_parse_group+0x224/0x280
Call Trace:
[ef82dd60] [c01d6a34] gfar_parse_group+0x224/0x280 (unreliable)
[ef82dd90] [c01d73a4] gfar_probe+0x284/0xfe0
The reason is that the commit also changed the allocation of the
Rx and error handling irq structs to be skipped for !MQ_MG_MODE.
In the !MQ_MG_MODE case, only the Tx irq struct is allocated.
Digging further, we see that MQ_MG_MODE is set only if we find
the OF compatible string "fsl,etsec2".
A quick grep in the dts directory shows lots of boards that support
Rx/Tx/Err, but without this specific compat string. And hence they
go after the unallocated Rx/Error structs and cause the above oops.
Hence such a change can not be deployed until all the dts files
are updated and sufficiently deployed. Further, the optimization
is of limited value, since the kmalloc'd struct in question has only
a single unsigned int, and an (IFNAMSIZ + 6) sized string.
Note that no changes to the freeing code are needed here, as it
already did an unconditional free of Rx/Tx/Error gfar_irqinfo.
Cc: Claudiu Manoil <claudiu.manoil@freescale.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/ethernet/freescale/gianfar.c | 16 |
1 files changed, 4 insertions, 12 deletions
diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c index 19c54a0acb56..75734bfed10f 100644 --- a/drivers/net/ethernet/freescale/gianfar.c +++ b/drivers/net/ethernet/freescale/gianfar.c @@ -580,19 +580,11 @@ static int gfar_parse_group(struct device_node *np, u32 *queue_mask; int i; - if (priv->mode == MQ_MG_MODE) { - for (i = 0; i < GFAR_NUM_IRQS; i++) { - grp->irqinfo[i] = kzalloc(sizeof(struct gfar_irqinfo), - GFP_KERNEL); - if (!grp->irqinfo[i]) - return -ENOMEM; - } - } else { - grp->irqinfo[GFAR_TX] = kzalloc(sizeof(struct gfar_irqinfo), - GFP_KERNEL); - if (!grp->irqinfo[GFAR_TX]) + for (i = 0; i < GFAR_NUM_IRQS; i++) { + grp->irqinfo[i] = kzalloc(sizeof(struct gfar_irqinfo), + GFP_KERNEL); + if (!grp->irqinfo[i]) return -ENOMEM; - grp->irqinfo[GFAR_RX] = grp->irqinfo[GFAR_ER] = NULL; } grp->regs = of_iomap(np, 0); |