clk: microchip: mpfs: don't reset disabled peripherals

The current clock driver for PolarFire SoC puts the hardware behind
"periph" clocks into reset if their clock is disabled. CONFIG_PM was
recently added to the riscv defconfig and exposed issues caused by this
behaviour, where the Cadence GEM was being put into reset between its
bringup & the PHY bringup:

https://lore.kernel.org/linux-riscv/9f4b057d-1985-5fd3-65c0-f944161c7792@microchip.com/

Fix this (for now) by removing the reset from mpfs_periph_clk_disable.

Fixes: 635e5e73370e ("clk: microchip: Add driver for Microchip PolarFire SoC")
Reviewed-by: Daire McNamara <daire.mcnamara@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20220411072340.740981-1-conor.dooley@microchip.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

diff --git a/drivers/clk/microchip/clk-mpfs.c b/drivers/clk/microchip/clk-mpfs.c
index aa1561b..744ef2b 100644 (file)
--- a/drivers/clk/microchip/clk-mpfs.c
+++ b/drivers/clk/microchip/clk-mpfs.c
@@ -200,10 +200,6 @@ static void mpfs_periph_clk_disable(struct clk_hw *hw)
 
        spin_lock_irqsave(&mpfs_clk_lock, flags);
 
-       reg = readl_relaxed(base_addr + REG_SUBBLK_RESET_CR);
-       val = reg | (1u << periph->shift);
-       writel_relaxed(val, base_addr + REG_SUBBLK_RESET_CR);
-
        reg = readl_relaxed(base_addr + REG_SUBBLK_CLOCK_CR);
        val = reg & ~(1u << periph->shift);
        writel_relaxed(val, base_addr + REG_SUBBLK_CLOCK_CR);