6.13-stable review patch. If anyone has any objections, please let me know.
------------------
From: Christian Bruel <christian.bruel@xxxxxxxxxxx>
[ Upstream commit fd75f371f3a1b04a33d2e750363d6ad76abf734e ]
Rework the workaround as the lookup tables always fits into the bitfield,
and the default values are defined by the hardware and cannot be 0:
Guard against false positive with a WARN_ON check to make the compiler
happy: The offset range is pre-checked against the sorted imp_lookup_table
values and overflow should not happen and would be caught by a warning and
return in error.
Also guard against a true positive found during the max_vswing lookup, as a
max vswing value can be 802000 or 803000 microvolt depending on the current
impedance. Therefore set the default impedence index.
Fixes: 2de679ecd724 ("phy: stm32: work around constant-value overflow assertion")
Signed-off-by: Christian Bruel <christian.bruel@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20250210103515.2598377-1-christian.bruel@xxxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/phy/st/phy-stm32-combophy.c | 38 ++++++++++++++---------------
1 file changed, 18 insertions(+), 20 deletions(-)
diff --git a/drivers/phy/st/phy-stm32-combophy.c b/drivers/phy/st/phy-stm32-combophy.c
index 49e9fa90a6819..607b4d607eb5e 100644
--- a/drivers/phy/st/phy-stm32-combophy.c
+++ b/drivers/phy/st/phy-stm32-combophy.c
@@ -111,6 +111,7 @@ static const struct clk_impedance imp_lookup[] = {
{ 4204000, { 511000, 609000, 706000, 802000 } },
{ 3999000, { 571000, 648000, 726000, 803000 } }
};
+#define DEFAULT_IMP_INDEX 3 /* Default impedance is 50 Ohm */
static int stm32_impedance_tune(struct stm32_combophy *combophy)
{
@@ -119,10 +120,9 @@ static int stm32_impedance_tune(struct stm32_combophy *combophy)
u8 imp_of, vswing_of;
u32 max_imp = imp_lookup[0].microohm;
u32 min_imp = imp_lookup[imp_size - 1].microohm;
- u32 max_vswing = imp_lookup[imp_size - 1].vswing[vswing_size - 1];
+ u32 max_vswing;
u32 min_vswing = imp_lookup[0].vswing[0];
u32 val;
- u32 regval;
if (!of_property_read_u32(combophy->dev->of_node, "st,output-micro-ohms", &val)) {
if (val < min_imp || val > max_imp) {
@@ -130,45 +130,43 @@ static int stm32_impedance_tune(struct stm32_combophy *combophy)
return -EINVAL;
}
- regval = 0;
- for (imp_of = 0; imp_of < ARRAY_SIZE(imp_lookup); imp_of++) {
- if (imp_lookup[imp_of].microohm <= val) {
- regval = FIELD_PREP(STM32MP25_PCIEPRG_IMPCTRL_OHM, imp_of);
+ for (imp_of = 0; imp_of < ARRAY_SIZE(imp_lookup); imp_of++)
+ if (imp_lookup[imp_of].microohm <= val)
break;
- }
- }
+
+ if (WARN_ON(imp_of == ARRAY_SIZE(imp_lookup)))
+ return -EINVAL;
dev_dbg(combophy->dev, "Set %u micro-ohms output impedance\n",
imp_lookup[imp_of].microohm);
regmap_update_bits(combophy->regmap, SYSCFG_PCIEPRGCR,
STM32MP25_PCIEPRG_IMPCTRL_OHM,
- regval);
- } else {
- regmap_read(combophy->regmap, SYSCFG_PCIEPRGCR, &val);
- imp_of = FIELD_GET(STM32MP25_PCIEPRG_IMPCTRL_OHM, val);
- }
+ FIELD_PREP(STM32MP25_PCIEPRG_IMPCTRL_OHM, imp_of));
+ } else
+ imp_of = DEFAULT_IMP_INDEX;
if (!of_property_read_u32(combophy->dev->of_node, "st,output-vswing-microvolt", &val)) {
+ max_vswing = imp_lookup[imp_of].vswing[vswing_size - 1];
+
if (val < min_vswing || val > max_vswing) {
dev_err(combophy->dev, "Invalid value %u for output vswing\n", val);
return -EINVAL;
}
- regval = 0;
- for (vswing_of = 0; vswing_of < ARRAY_SIZE(imp_lookup[imp_of].vswing); vswing_of++) {
- if (imp_lookup[imp_of].vswing[vswing_of] >= val) {
- regval = FIELD_PREP(STM32MP25_PCIEPRG_IMPCTRL_VSWING, vswing_of);
+ for (vswing_of = 0; vswing_of < ARRAY_SIZE(imp_lookup[imp_of].vswing); vswing_of++)
+ if (imp_lookup[imp_of].vswing[vswing_of] >= val)
break;
- }
- }
+
+ if (WARN_ON(vswing_of == ARRAY_SIZE(imp_lookup[imp_of].vswing)))
+ return -EINVAL;
dev_dbg(combophy->dev, "Set %u microvolt swing\n",
imp_lookup[imp_of].vswing[vswing_of]);
regmap_update_bits(combophy->regmap, SYSCFG_PCIEPRGCR,
STM32MP25_PCIEPRG_IMPCTRL_VSWING,
- regval);
+ FIELD_PREP(STM32MP25_PCIEPRG_IMPCTRL_VSWING, vswing_of));
}
return 0;
--
2.39.5
