[PATCH] clk: qcom: gcc-sdm845: Use floor ops for sdcc clks

* [PATCH] clk: qcom: gcc-sdm845: Use floor ops for sdcc clks
@ 2019-08-30 19:51 Stephen Boyd
  2019-08-30 21:34 ` Doug Anderson
  2019-09-09 10:25 ` Stephen Boyd
  0 siblings, 2 replies; 6+ messages in thread
From: Stephen Boyd @ 2019-08-30 19:51 UTC (permalink / raw)
  To: Michael Turquette, Stephen Boyd
  Cc: linux-kernel, linux-clk, linux-arm-msm, Douglas Anderson, Taniya Das

Some MMC cards fail to enumerate properly when inserted into an MMC slot
on sdm845 devices. This is because the clk ops for qcom clks round the
frequency up to the nearest rate instead of down to the nearest rate.
For example, the MMC driver requests a frequency of 52MHz from
clk_set_rate() but the qcom implementation for these clks rounds 52MHz
up to the next supported frequency of 100MHz. The MMC driver could be
modified to request clk rate ranges but for now we can fix this in the
clk driver by changing the rounding policy for this clk to be round down
instead of round up.

Fixes: 06391eddb60a ("clk: qcom: Add Global Clock controller (GCC) driver for SDM845")
Reported-by: Douglas Anderson <dianders@chromium.org>
Cc: Taniya Das <tdas@codeaurora.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
---

I suppose we need to do this for all the sdc clks in qcom driver?

 drivers/clk/qcom/gcc-sdm845.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/qcom/gcc-sdm845.c b/drivers/clk/qcom/gcc-sdm845.c
index 7131dcf9b060..95be125c3bdd 100644
--- a/drivers/clk/qcom/gcc-sdm845.c
+++ b/drivers/clk/qcom/gcc-sdm845.c
@@ -685,7 +685,7 @@ static struct clk_rcg2 gcc_sdcc2_apps_clk_src = {
 		.name = "gcc_sdcc2_apps_clk_src",
 		.parent_names = gcc_parent_names_10,
 		.num_parents = 5,
-		.ops = &clk_rcg2_ops,
+		.ops = &clk_rcg2_floor_ops,
 	},
 };
 
@@ -709,7 +709,7 @@ static struct clk_rcg2 gcc_sdcc4_apps_clk_src = {
 		.name = "gcc_sdcc4_apps_clk_src",
 		.parent_names = gcc_parent_names_0,
 		.num_parents = 4,
-		.ops = &clk_rcg2_ops,
+		.ops = &clk_rcg2_floor_ops,
 	},
 };
 
-- 
Sent by a computer through tubes


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