FAILED: patch "[PATCH] phy: cadence: cdns-dphy: Update calibration wait time for" failed to apply to 5.4-stable tree

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 2c27aaee934a1b5229152fe33a14f1fdf50da143
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025101628-scribing-handwork-22ac@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 2c27aaee934a1b5229152fe33a14f1fdf50da143 Mon Sep 17 00:00:00 2001
From: Devarsh Thakkar <[email protected]>
Date: Fri, 4 Jul 2025 18:29:15 +0530
Subject: [PATCH] phy: cadence: cdns-dphy: Update calibration wait time for
startup state machine

Do read-modify-write so that we re-use the characterized reset value as specified in TRM [1] to program calibration wait time which defines number of cycles to wait for after startup state machine is in bandgap enable state.

This fixes PLL lock timeout error faced while using RPi DSI Panel on TI's AM62L and J721E SoC since earlier calibration wait time was getting overwritten to zero value thus failing the PLL to lockup and causing timeout.

[1] AM62P TRM (Section 14.8.6.3.2.1.1 DPHY_TX_DPHYTX_CMN0_CMN_DIG_TBIT2):

index da8de0a9d086..24a25606996c 100644
@@ -30,6 +30,7 @@
 
 #define DPHY_CMN_SSM			DPHY_PMA_CMN(0x20)
 #define DPHY_CMN_SSM_EN			BIT(0)
+#define DPHY_CMN_SSM_CAL_WAIT_TIME	GENMASK(8, 1)
 #define DPHY_CMN_TX_MODE_EN		BIT(9)
 
 #define DPHY_CMN_PWM			DPHY_PMA_CMN(0x40)

@@ -410,7 +411,8 @@ static int cdns_dphy_power_on(struct phy *phy)
 	writel(reg, dphy->regs + DPHY_BAND_CFG);
 
 	/* Start TX state machine. */
-	writel(DPHY_CMN_SSM_EN | DPHY_CMN_TX_MODE_EN,
+	reg = readl(dphy->regs + DPHY_CMN_SSM);
+	writel((reg & DPHY_CMN_SSM_CAL_WAIT_TIME) | DPHY_CMN_SSM_EN | DPHY_CMN_TX_MODE_EN,
 	       dphy->regs + DPHY_CMN_SSM);
 
 	ret = cdns_dphy_wait_for_pll_lock(dphy);