6.13-stable review patch. If anyone has any objections, please let me know.
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From: Christian Bruel christian.bruel@foss.st.com
[ 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@foss.st.com Link: https://lore.kernel.org/r/20250210103515.2598377-1-christian.bruel@foss.st.c... Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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;