Re: [PATCH] net: ibm: emac: Fix some error handling path in 'emac_probe()'

From: Christophe JAILLET
Date: Sun Aug 20 2017 - 00:41:47 EST


Le 19/08/2017 à 15:22, Christian Lamparter a écrit :
On Saturday, August 19, 2017 1:07:57 AM CEST Christophe JAILLET wrote:
If 'irq_of_parse_and_map()' or 'of_address_to_resource()' fail, 'err' is
known to be 0 at this point.
So return -ENODEV instead in the first case and propagate the error
returned by 'of_address_to_resource()' in the 2nd case.

While at it, turn a 'err != 0' test into an equivalent 'err' to be more
consistent.

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
drivers/net/ethernet/ibm/emac/core.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/ibm/emac/core.c b/drivers/net/ethernet/ibm/emac/core.c
index 95135d20458f..1af56a97fb47 100644
--- a/drivers/net/ethernet/ibm/emac/core.c
+++ b/drivers/net/ethernet/ibm/emac/core.c
[...]
/* Map EMAC regs */
- if (of_address_to_resource(np, 0, &dev->rsrc_regs)) {
+ err = of_address_to_resource(np, 0, &dev->rsrc_regs);
+ if (err) {
printk(KERN_ERR "%pOF: Can't get registers address\n", np);
goto err_irq_unmap;
}
// TODO : request_mem_region
dev->emacp = ioremap(dev->rsrc_regs.start,
resource_size(&dev->rsrc_regs));
...
If you want to go for 101%: you could get rid of this block
altogether by doing:
dev->emacp = of_iomap(np, 0);

Note1:
This will also make the rsrc_regs variable in the emac_instance
struct redundant. So simply remove it from the core.h.

Note2: if you want to go for 110%, you could replace this with
platform_get_resource() and devm_ioremap_resource() (if you
are interested, take a look at devm_ioremap_resource's kdoc
it has an example).

Thanks,
Christian

Hi,

Thanks for the review and comments.

I've sent a v2 to go for 101% which axes some lines of code.

I won't propose anything for your other proposal. Sounds great but involves more changes in the error handling path and in the remove function.
I don't have the hardware, so I won't be able to test this bigger change.

Christophe