[PATCH] ram: k3-ddrss: drop debug() in timing-sensitive sequence

[PATCH] ram: k3-ddrss: drop debug() in timing-sensitive sequence

[Théo Lebrun]

Those debug() calls might be useful, but beware. They can cause the DDR
controller to hang if we do not run the sequence quickly enough.

They usually are not an issue with upstream U-Boot and the default DDR
config, but they have become troublesome with custom DDR configs.

Drop those debug() statements that shouldn't be present in
time-sensitive code, to avoid anyone else falling into the trap.

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
---
 drivers/ram/k3-ddrss/k3-ddrss.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/ram/k3-ddrss/k3-ddrss.c b/drivers/ram/k3-ddrss/k3-ddrss.c
index 525b6d5b79fce18819946e1714e98290057ccccf..6e9202b957962ec95fbad2469a0ef8c8557c5d95 100644
--- a/drivers/ram/k3-ddrss/k3-ddrss.c
+++ b/drivers/ram/k3-ddrss/k3-ddrss.c
@@ -216,9 +216,6 @@ static void k3_lpddr4_freq_update(struct k3_ddrss_desc *ddrss)
 		req_type = readl(ddrss->ddrss_ctrl_mmr +
 				 CTRLMMR_DDR4_FSP_CLKCHNG_REQ_OFFS + ddrss->instance * 0x10) & 0x03;
 
-		debug("%s: received freq change req: req type = %d, req no. = %d, instance = %d\n",
-		      __func__, req_type, counter, ddrss->instance);
-
 		if (req_type == 1)
 			clk_set_rate(&ddrss->ddr_clk, ddrss->ddr_freq1);
 		else if (req_type == 2)
@@ -245,8 +242,6 @@ static void k3_lpddr4_ack_freq_upd_req(const lpddr4_privatedata *pd)
 {
 	struct k3_ddrss_desc *ddrss = (struct k3_ddrss_desc *)pd->ddr_instance;
 
-	debug("--->>> LPDDR4 Initialization is in progress ... <<<---\n");
-
 	switch (ddrss->dram_class) {
 	case DENALI_CTL_0_DRAM_CLASS_DDR4:
 		break;

---
base-commit: 2bf2615b8004e4a296fb25498ad0c183fd5c7b94
change-id: 20241115-k3-debug-30505f24e214

Best regards,
-- 
Théo Lebrun <theo.lebrun@bootlin.com>

Re: [PATCH] ram: k3-ddrss: drop debug() in timing-sensitive sequence

[Tom Rini]

On Fri, 15 Nov 2024 10:43:15 +0100, Théo Lebrun wrote:

> Those debug() calls might be useful, but beware. They can cause the DDR
> controller to hang if we do not run the sequence quickly enough.
> 
> They usually are not an issue with upstream U-Boot and the default DDR
> config, but they have become troublesome with custom DDR configs.
> 
> Drop those debug() statements that shouldn't be present in
> time-sensitive code, to avoid anyone else falling into the trap.
> 
> [...]

Applied to u-boot/next, thanks!

-- 
Tom