2022-02-11 11:33:05

by Robert Marko

Subject: [PATCH] clk: qcom: ipq8074: Use floor ops for SDCC1 clock

From: Dirk Buchwalder <[email protected]>

Use floor ops on SDCC1 APPS clock in order to round down selected clock
frequency and avoid overclocking SD/eMMC cards.

For example, currently HS200 cards were failling tuning as they were
actually being clocked at 384MHz instead of 192MHz.
This caused some boards to disable 1.8V I/O and force the eMMC into the
standard HS mode (50MHz) and that appeared to work despite the eMMC being
overclocked to 96Mhz in that case.

There was a previous commit to use floor ops on SDCC clocks, but it looks
to have only covered SDCC2 clock.

Fixes: 9607f6224b39 ("clk: qcom: ipq8074: add PCIE, USB and SDCC clocks")

Signed-off-by: Dirk Buchwalder <[email protected]>
Signed-off-by: Robert Marko <[email protected]>
---
drivers/clk/qcom/gcc-ipq8074.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/qcom/gcc-ipq8074.c b/drivers/clk/qcom/gcc-ipq8074.c
index 1e493f19fa44..c24e33321f72 100644
--- a/drivers/clk/qcom/gcc-ipq8074.c
+++ b/drivers/clk/qcom/gcc-ipq8074.c
@@ -1074,7 +1074,7 @@ static struct clk_rcg2 sdcc1_apps_clk_src = {
.name = "sdcc1_apps_clk_src",
.parent_names = gcc_xo_gpll0_gpll2_gpll0_out_main_div2,
.num_parents = 4,
- .ops = &clk_rcg2_ops,
+ .ops = &clk_rcg2_floor_ops,
},
};

--
2.35.1

2022-02-18 00:43:04

by Stephen Boyd

Subject: Re: [PATCH] clk: qcom: ipq8074: Use floor ops for SDCC1 clock

Quoting Robert Marko (2022-02-10 09:31:00)
> From: Dirk Buchwalder <[email protected]>
>
> Use floor ops on SDCC1 APPS clock in order to round down selected clock
> frequency and avoid overclocking SD/eMMC cards.
>
> For example, currently HS200 cards were failling tuning as they were
> actually being clocked at 384MHz instead of 192MHz.
> This caused some boards to disable 1.8V I/O and force the eMMC into the
> standard HS mode (50MHz) and that appeared to work despite the eMMC being
> overclocked to 96Mhz in that case.
>
> There was a previous commit to use floor ops on SDCC clocks, but it looks
> to have only covered SDCC2 clock.
>
> Fixes: 9607f6224b39 ("clk: qcom: ipq8074: add PCIE, USB and SDCC clocks")
>
> Signed-off-by: Dirk Buchwalder <[email protected]>
> Signed-off-by: Robert Marko <[email protected]>
> ---

Reviewed-by: Stephen Boyd <[email protected]>

2022-02-24 21:25:02

by Bjorn Andersson

Subject: Re: (subset) [PATCH] clk: qcom: ipq8074: Use floor ops for SDCC1 clock

On Thu, 10 Feb 2022 18:31:00 +0100, Robert Marko wrote:
> From: Dirk Buchwalder <[email protected]>
>
> Use floor ops on SDCC1 APPS clock in order to round down selected clock
> frequency and avoid overclocking SD/eMMC cards.
>
> For example, currently HS200 cards were failling tuning as they were
> actually being clocked at 384MHz instead of 192MHz.
> This caused some boards to disable 1.8V I/O and force the eMMC into the
> standard HS mode (50MHz) and that appeared to work despite the eMMC being
> overclocked to 96Mhz in that case.
>
> [...]

Applied, thanks!

[1/1] clk: qcom: ipq8074: Use floor ops for SDCC1 clock
commit: b77d8306d84f83d1da68028a68c91da9c867b6f6

Best regards,
--
Bjorn Andersson <[email protected]>