[PATCH] ram: k3-ddrss: do not touch ctrl regs during training

During LPDDR initialization we will loop through a series of frequency changes in order to train at the various operating frequencies. During this training, accessing the DRAM_CLASS bitfield could happen during a frequency change and cause the read to hang.
Store the DRAM type into the main structure to avoid multiple readings while the independent phy is training.
Signed-off-by: Bryan Brattlof bb@ti.com --- drivers/ram/k3-ddrss/k3-ddrss.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/drivers/ram/k3-ddrss/k3-ddrss.c b/drivers/ram/k3-ddrss/k3-ddrss.c index 7e445d2b737b3..b54557f02cce1 100644 --- a/drivers/ram/k3-ddrss/k3-ddrss.c +++ b/drivers/ram/k3-ddrss/k3-ddrss.c @@ -138,6 +138,7 @@ struct k3_ddrss_desc { u32 ddr_freq1; u32 ddr_freq2; u32 ddr_fhs_cnt; + u32 dram_class; struct udevice *vtt_supply; u32 instance; lpddr4_obj *driverdt; @@ -243,14 +244,11 @@ static void k3_lpddr4_freq_update(struct k3_ddrss_desc *ddrss)
static void k3_lpddr4_ack_freq_upd_req(const lpddr4_privatedata *pd) { - u32 dram_class; struct k3_ddrss_desc *ddrss = (struct k3_ddrss_desc *)pd->ddr_instance;
debug("--->>> LPDDR4 Initialization is in progress ... <<<---\n");
- dram_class = k3_lpddr4_read_ddr_type(pd); - - switch (dram_class) { + switch (ddrss->dram_class) { case DENALI_CTL_0_DRAM_CLASS_DDR4: break; case DENALI_CTL_0_DRAM_CLASS_LPDDR4: @@ -263,13 +261,12 @@ static void k3_lpddr4_ack_freq_upd_req(const lpddr4_privatedata *pd)
static int k3_ddrss_init_freq(struct k3_ddrss_desc *ddrss) { - u32 dram_class; int ret; lpddr4_privatedata *pd = &ddrss->pd;
- dram_class = k3_lpddr4_read_ddr_type(pd); + ddrss->dram_class = k3_lpddr4_read_ddr_type(pd);
- switch (dram_class) { + switch (ddrss->dram_class) { case DENALI_CTL_0_DRAM_CLASS_DDR4: /* Set to ddr_freq1 from DT for DDR4 */ ret = clk_set_rate(&ddrss->ddr_clk, ddrss->ddr_freq1);
base-commit: 13aa090b87a0fbdfe690011669b9fdb96bb1ccc7

On Mon, Jul 17, 2023 at 05:15:26PM -0500, Bryan Brattlof wrote:
During LPDDR initialization we will loop through a series of frequency changes in order to train at the various operating frequencies. During this training, accessing the DRAM_CLASS bitfield could happen during a frequency change and cause the read to hang.
Store the DRAM type into the main structure to avoid multiple readings while the independent phy is training.
Signed-off-by: Bryan Brattlof bb@ti.com
Applied to u-boot/master, thanks!
participants (2)
-
Bryan Brattlof
-
Tom Rini