Messages in this thread Patch in this message | | | From | Rasmus Villemoes <> | Subject | [PATCH] net: stmmac: dwmac-meson8b: fix meson8b_devm_clk_prepare_enable() | Date | Fri, 4 Nov 2022 09:30:04 +0100 |
| |
There are two problems with meson8b_devm_clk_prepare_enable(), introduced in a54dc4a49045 (net: stmmac: dwmac-meson8b: Make the clock enabling code re-usable):
- It doesn't pass the clk argument, but instead always the rgmii_tx_clk of the device.
- It silently ignores the return value of devm_add_action_or_reset().
The former didn't become an actual bug until another user showed up in the next commit, 9308c47640d5 (net: stmmac: dwmac-meson8b: add support for the RX delay configuration). The latter means the callers could end up with the clock not actually prepared/enabled.
Fixes: a54dc4a49045 (net: stmmac: dwmac-meson8b: Make the clock enabling code re-usable) Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> --- Not tested in any way, just stumbled on this which didn't seem right.
It seems that the timing_adj_clk could be changed (with a bit of refactoring) to use devm_clk_get_enabled() - i.e. don't make it optional, but only get/prepare/enable it in the (delay_config & PRG_ETH0_ADJ_ENABLE) branch where the code actually requires it.
But since there's no official devm_clk_prepare_enable, and the rgmii_tx_clk isn't obtained via a clk_get, I don't see a simple way to avoid this private implmentation of devm_clk_prepare_enable().
drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c index c7a6588d9398..e8b507f88fbc 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c @@ -272,11 +272,9 @@ static int meson8b_devm_clk_prepare_enable(struct meson8b_dwmac *dwmac, if (ret) return ret; - devm_add_action_or_reset(dwmac->dev, - (void(*)(void *))clk_disable_unprepare, - dwmac->rgmii_tx_clk); - - return 0; + return devm_add_action_or_reset(dwmac->dev, + (void(*)(void *))clk_disable_unprepare, + clk); } static int meson8b_init_rgmii_delays(struct meson8b_dwmac *dwmac) -- 2.37.2
| |