Thread (6 messages) 6 messages, 5 authors, 2025-05-16

Re: [PATCH v2] phy: phy-rockchip-samsung-hdptx: Fix PHY PLL output 50.25MHz error

From: Diederik de Haas <hidden>
Date: 2025-05-16 15:36:25
Also in: linux-phy, linux-rockchip, lkml

Hi,

On Sun Apr 27, 2025 at 11:51 AM CEST, Algea Cao wrote:
quoted hunk ↗ jump to hunk
When using HDMI PLL frequency division coefficient at 50.25MHz
that is calculated by rk_hdptx_phy_clk_pll_calc(), it fails to
get PHY LANE lock. Although the calculated values are within the
allowable range of PHY PLL configuration.

In order to fix the PHY LANE lock error and provide the expected
50.25MHz output, manually compute the required PHY PLL frequency
division coefficient and add it to ropll_tmds_cfg configuration
table.

Signed-off-by: Algea Cao <redacted>
Reviewed-by: Cristian Ciocaltea <redacted>

---
 drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c | 2 ++
 1 file changed, 2 insertions(+)
diff --git a/drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c b/drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c
index fe7c05748356..77236f012a1f 100644
--- a/drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c
+++ b/drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c
@@ -476,6 +476,8 @@ static const struct ropll_config ropll_tmds_cfg[] = {
 	  1, 1, 0, 0x20, 0x0c, 1, 0x0e, 0, 0, },
 	{ 650000, 162, 162, 1, 1, 11, 1, 1, 1, 1, 1, 1, 1, 54, 0, 16, 4, 1,
 	  1, 1, 0, 0x20, 0x0c, 1, 0x0e, 0, 0, },
+	{ 502500, 84, 84, 1, 1, 7, 1, 1, 1, 1, 1, 1, 1, 11, 1, 4, 5,
+	  4, 11, 1, 0, 0x20, 0x0c, 1, 0x0e, 0, 0, },
 	{ 337500, 0x70, 0x70, 1, 1, 0xf, 1, 1, 1, 1, 1, 1, 1, 0x2, 0, 0x01, 5,
 	  1, 1, 1, 0, 0x20, 0x0c, 1, 0x0e, 0, 0, },
 	{ 400000, 100, 100, 1, 1, 11, 1, 1, 0, 1, 0, 1, 1, 0x9, 0, 0x05, 0,
I found this patch in the 'fixes' branch in linux-phy:
https://git.kernel.org/pub/scm/linux/kernel/git/phy/linux-phy.git/commit/?h=fixes&id=f9475055b11c0c70979bd1667a76b2ebae638eb7

In the 'next' branch in linux-phy, I found this commit:
0edf9d2bb9b4 ("phy: rockchip: samsung-hdptx: Avoid Hz<->hHz unit conversion overhead")
https://git.kernel.org/pub/scm/linux/kernel/git/phy/linux-phy.git/commit/?h=next&id=0edf9d2bb9b4ba7566dfdc7605883e04575129d9

Where the values in ropll_tmds_cfg are converted from hHz to Hz and the
data type changes from u32 to unsigned long long.
But AFAICT it does NOT convert this '502500' value, which IIUC means
most values are in Hz, while this one is in hHz.

Am I missing something or should this new value also be converted?

Cheers,
  Diederik

Attachments

Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help