[U-Boot] [PATCH] NET: designware: fix clock enable

[U-Boot] [PATCH] NET: designware: fix clock enable

[Eugeniy Paltsev]

After commit ba1f966725223 "net: designware: add clock support"
we got NET broken on axs101 and axs103 platforms.

Some clock don't support gating so their clock drivers don't
implement .enable/.disable callbacks. In such case clk_enable
returns -ENOSYS.
Also some clock drivers implement .enable/.disable callbacks not for all
clock IDs and return -ENOSYS (or -ENOTSUPP) for others.

If we have such clock in 'clocks' list of designware ethernet controller
node we fail to probe designware ethernet.

Fix it.

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
---
 drivers/net/designware.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/designware.c b/drivers/net/designware.c
index 6d53071..43670a7 100644
--- a/drivers/net/designware.c
+++ b/drivers/net/designware.c
@@ -684,7 +684,7 @@ int designware_eth_probe(struct udevice *dev)
 				break;
 
 			err = clk_enable(&priv->clocks[i]);
-			if (err) {
+			if (err && err != -ENOSYS && err != -ENOTSUPP) {
 				pr_err("failed to enable clock %d\n", i);
 				clk_free(&priv->clocks[i]);
 				goto clk_err;
-- 
2.9.3

[U-Boot] [PATCH] NET: designware: fix clock enable

[Patrice CHOTARD]

Hi Eugeniy

On 02/06/2018 03:12 PM, Eugeniy Paltsev wrote:
> After commit ba1f966725223 "net: designware: add clock support"
> we got NET broken on axs101 and axs103 platforms.
> 
> Some clock don't support gating so their clock drivers don't
> implement .enable/.disable callbacks. In such case clk_enable
> returns -ENOSYS.
> Also some clock drivers implement .enable/.disable callbacks not for all
> clock IDs and return -ENOSYS (or -ENOTSUPP) for others.
> 
> If we have such clock in 'clocks' list of designware ethernet controller
> node we fail to probe designware ethernet.
> 
> Fix it.
> 
> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
> ---
>   drivers/net/designware.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/designware.c b/drivers/net/designware.c
> index 6d53071..43670a7 100644
> --- a/drivers/net/designware.c
> +++ b/drivers/net/designware.c
> @@ -684,7 +684,7 @@ int designware_eth_probe(struct udevice *dev)
>   				break;
>   
>   			err = clk_enable(&priv->clocks[i]);
> -			if (err) {
> +			if (err && err != -ENOSYS && err != -ENOTSUPP) {
>   				pr_err("failed to enable clock %d\n", i);
>   				clk_free(&priv->clocks[i]);
>   				goto clk_err;
> 

Reviewed-by: Patrice Chotard <patrice.chotard@st.com>

Thanks

[U-Boot] [PATCH] NET: designware: fix clock enable

[Joe Hershberger]

On Tue, Feb 6, 2018 at 8:12 AM, Eugeniy Paltsev
<Eugeniy.Paltsev@synopsys.com> wrote:
> After commit ba1f966725223 "net: designware: add clock support"
> we got NET broken on axs101 and axs103 platforms.
>
> Some clock don't support gating so their clock drivers don't
> implement .enable/.disable callbacks. In such case clk_enable
> returns -ENOSYS.
> Also some clock drivers implement .enable/.disable callbacks not for all
> clock IDs and return -ENOSYS (or -ENOTSUPP) for others.
>
> If we have such clock in 'clocks' list of designware ethernet controller
> node we fail to probe designware ethernet.
>
> Fix it.
>
> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>

Acked-by: Joe Hershberger <joe.hershberger@ni.com>

[U-Boot] [PATCH] NET: designware: fix clock enable

[Dr. Philipp Tomsich]

> On 6 Feb 2018, at 15:12, Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> wrote:
> 
> After commit ba1f966725223 "net: designware: add clock support"
> we got NET broken on axs101 and axs103 platforms.
> 
> Some clock don't support gating so their clock drivers don't
> implement .enable/.disable callbacks. In such case clk_enable
> returns -ENOSYS.
> Also some clock drivers implement .enable/.disable callbacks not for all
> clock IDs and return -ENOSYS (or -ENOTSUPP) for others.
> 
> If we have such clock in 'clocks' list of designware ethernet controller
> node we fail to probe designware ethernet.
> 
> Fix it.
> 
> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>

Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>

See below for recommended changes.

> ---
> drivers/net/designware.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/designware.c b/drivers/net/designware.c
> index 6d53071..43670a7 100644
> --- a/drivers/net/designware.c
> +++ b/drivers/net/designware.c
> @@ -684,7 +684,7 @@ int designware_eth_probe(struct udevice *dev)
> 				break;
> 
> 			err = clk_enable(&priv->clocks[i]);
> -			if (err) {
> +			if (err && err != -ENOSYS && err != -ENOTSUPP) {

I agree on the ENOSYS, but not the ENOTSUPP: if an enable function
exists, it should explicitly handle the requested clock (even if it is just a
no-op due to the driver knowing that it is always enabled).

Just as a side-note: most clock drivers return ENOENT, if they don’t
know about a specific clock… whereas ENOTSUPP should be returned
if a clock is known, but the specific operation on the clock is not supported
(e.g. clk_disable on an always-on clock … or one that is critical to the
system such as a fundamental PLL).

Thanks,
Philipp.

> 				pr_err("failed to enable clock %d\n", i);
> 				clk_free(&priv->clocks[i]);
> 				goto clk_err;
> -- 
> 2.9.3
> 
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> U-Boot mailing list
> U-Boot at lists.denx.de
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[U-Boot] NET: designware: fix clock enable

[Joe Hershberger]

Hi Eugeniy,

https://patchwork.ozlabs.org/patch/869785/ was applied to http://git.denx.de/?p=u-boot/u-boot-net.git

Thanks!
-Joe