[PATCH 6.13 225/623] clk: analogbits: Fix incorrect calculation of vco rate delta

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



6.13-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Bo Gan <ganboing@xxxxxxxxx>

[ Upstream commit d7f12857f095ef38523399d47e68787b357232f6 ]

In wrpll_configure_for_rate() we try to determine the best PLL
configuration for a target rate. However, in the loop where we try
values of R, we should compare the derived `vco` with `target_vco_rate`.
However, we were in fact comparing it with `target_rate`, which is
actually after Q shift. This is incorrect, and sometimes can result in
suboptimal clock rates. Fix it.

Fixes: 7b9487a9a5c4 ("clk: analogbits: add Wide-Range PLL library")
Signed-off-by: Bo Gan <ganboing@xxxxxxxxx>
Link: https://lore.kernel.org/r/20240830061639.2316-1-ganboing@xxxxxxxxx
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/clk/analogbits/wrpll-cln28hpc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/analogbits/wrpll-cln28hpc.c b/drivers/clk/analogbits/wrpll-cln28hpc.c
index 65d422a588e1f..9d178afc73bdd 100644
--- a/drivers/clk/analogbits/wrpll-cln28hpc.c
+++ b/drivers/clk/analogbits/wrpll-cln28hpc.c
@@ -292,7 +292,7 @@ int wrpll_configure_for_rate(struct wrpll_cfg *c, u32 target_rate,
 			vco = vco_pre * f;
 		}
 
-		delta = abs(target_rate - vco);
+		delta = abs(target_vco_rate - vco);
 		if (delta < best_delta) {
 			best_delta = delta;
 			best_r = r;
-- 
2.39.5







[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux