2019-11-06 10:14:00

by Christophe Roullier

Subject: [PATCH V3 net-next 1/4] net: ethernet: stmmac: Add support for syscfg clock

Add optional support for syscfg clock in dwmac-stm32.c
Now Syscfg clock is activated automatically when syscfg
registers are used

Signed-off-by: Christophe Roullier <[email protected]>
---
.../net/ethernet/stmicro/stmmac/dwmac-stm32.c | 28 +++++++++++--------
1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
index 4ef041bdf6a1..be7d58d83cfa 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
@@ -152,19 +152,24 @@ static int stm32mp1_clk_prepare(struct stm32_dwmac *dwmac, bool prepare)
int ret = 0;

if (prepare) {
- ret = clk_prepare_enable(dwmac->syscfg_clk);
- if (ret)
- return ret;
-
+ if (dwmac->syscfg_clk) {
+ ret = clk_prepare_enable(dwmac->syscfg_clk);
+ if (ret)
+ return ret;
+ }
if (dwmac->clk_eth_ck) {
ret = clk_prepare_enable(dwmac->clk_eth_ck);
if (ret) {
- clk_disable_unprepare(dwmac->syscfg_clk);
+ if (dwmac->syscfg_clk)
+ clk_disable_unprepare
+ (dwmac->syscfg_clk);
return ret;
}
}
} else {
- clk_disable_unprepare(dwmac->syscfg_clk);
+ if (dwmac->syscfg_clk)
+ clk_disable_unprepare(dwmac->syscfg_clk);
+
if (dwmac->clk_eth_ck)
clk_disable_unprepare(dwmac->clk_eth_ck);
}
@@ -320,12 +325,10 @@ static int stm32mp1_parse_data(struct stm32_dwmac *dwmac,
return PTR_ERR(dwmac->clk_ethstp);
}

- /* Clock for sysconfig */
+ /* Optional Clock for sysconfig */
dwmac->syscfg_clk = devm_clk_get(dev, "syscfg-clk");
- if (IS_ERR(dwmac->syscfg_clk)) {
- dev_err(dev, "No syscfg clock provided...\n");
- return PTR_ERR(dwmac->syscfg_clk);
- }
+ if (IS_ERR(dwmac->syscfg_clk))
+ dwmac->syscfg_clk = NULL;

/* Get IRQ information early to have an ability to ask for deferred
* probe if needed before we went too far with resource allocation.
@@ -436,7 +439,8 @@ static int stm32mp1_suspend(struct stm32_dwmac *dwmac)
return ret;

clk_disable_unprepare(dwmac->clk_tx);
- clk_disable_unprepare(dwmac->syscfg_clk);
+ if (dwmac->syscfg_clk)
+ clk_disable_unprepare(dwmac->syscfg_clk);
if (dwmac->clk_eth_ck)
clk_disable_unprepare(dwmac->clk_eth_ck);

--
2.17.1

2019-11-06 18:14:00

by Andrew Lunn

Subject: Re: [PATCH V3 net-next 1/4] net: ethernet: stmmac: Add support for syscfg clock

On Wed, Nov 06, 2019 at 11:12:17AM +0100, Christophe Roullier wrote:
> Add optional support for syscfg clock in dwmac-stm32.c
> Now Syscfg clock is activated automatically when syscfg
> registers are used
>
> Signed-off-by: Christophe Roullier <[email protected]>
> ---
> .../net/ethernet/stmicro/stmmac/dwmac-stm32.c | 28 +++++++++++--------
> 1 file changed, 16 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
> index 4ef041bdf6a1..be7d58d83cfa 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
> @@ -152,19 +152,24 @@ static int stm32mp1_clk_prepare(struct stm32_dwmac *dwmac, bool prepare)
> int ret = 0;
>
> if (prepare) {
> - ret = clk_prepare_enable(dwmac->syscfg_clk);
> - if (ret)
> - return ret;
> -
> + if (dwmac->syscfg_clk) {
> + ret = clk_prepare_enable(dwmac->syscfg_clk);
> + if (ret)
> + return ret;
> + }

Hi Christophe

I think you did not understand what i said. clk_prepare_enable() is
happy to take a NULL pointer. So you don't need this new guard. You
don't need this change at all.

> if (dwmac->clk_eth_ck) {
> ret = clk_prepare_enable(dwmac->clk_eth_ck);
> if (ret) {
> - clk_disable_unprepare(dwmac->syscfg_clk);
> + if (dwmac->syscfg_clk)
> + clk_disable_unprepare
> + (dwmac->syscfg_clk);

clk_disable_unprepare() is happy to take a NULL pointer...

Andrew