3 files changed, 12 insertions, 19 deletions

diff --git a/embassy-stm32/src/adc/v2.rs b/embassy-stm32/src/adc/v2.rs
index 30ac5d872..2cdaa00dc 100644
--- a/embassy-stm32/src/adc/v2.rs
+++ b/embassy-stm32/src/adc/v2.rs
@@ -94,7 +94,6 @@ impl Prescaler {
 
 pub struct Adc<'d, T: Instance> {
     sample_time: SampleTime,
-    resolution: Resolution,
     phantom: PhantomData<&'d mut T>,
 }
 
@@ -120,7 +119,6 @@ where
 
         Self {
             sample_time: Default::default(),
-            resolution: Resolution::default(),
             phantom: PhantomData,
         }
     }
@@ -130,7 +128,9 @@ where
     }
 
     pub fn set_resolution(&mut self, resolution: Resolution) {
-        self.resolution = resolution;
+        unsafe {
+            T::regs().cr1().modify(|reg| reg.set_res(resolution.into()));
+        }
     }
 
     /// Enables internal voltage reference and returns [VrefInt], which can be used in
@@ -214,7 +214,6 @@ where
 
     unsafe fn read_channel(&mut self, channel: u8) -> u16 {
         // Configure ADC
-        T::regs().cr1().modify(|reg| reg.set_res(self.resolution.into()));
 
         // Select channel
         T::regs().sqr3().write(|reg| reg.set_sq(0, channel));
diff --git a/embassy-stm32/src/adc/v3.rs b/embassy-stm32/src/adc/v3.rs
index 7962f2414..c6898f54a 100644
--- a/embassy-stm32/src/adc/v3.rs
+++ b/embassy-stm32/src/adc/v3.rs
@@ -62,7 +62,6 @@ impl<T: Instance> super::sealed::AdcPin<T> for Vbat {
 
 pub struct Adc<'d, T: Instance> {
     sample_time: SampleTime,
-    resolution: Resolution,
     phantom: PhantomData<&'d mut T>,
 }
 
@@ -99,7 +98,6 @@ impl<'d, T: Instance> Adc<'d, T> {
 
         Self {
             sample_time: Default::default(),
-            resolution: Resolution::default(),
             phantom: PhantomData,
         }
     }
@@ -145,7 +143,12 @@ impl<'d, T: Instance> Adc<'d, T> {
     }
 
     pub fn set_resolution(&mut self, resolution: Resolution) {
-        self.resolution = resolution;
+        unsafe {
+            #[cfg(not(stm32g0))]
+            T::regs().cfgr().modify(|reg| reg.set_res(resolution.into()));
+            #[cfg(stm32g0)]
+            T::regs().cfgr1().modify(|reg| reg.set_res(resolution.into()));
+        }
     }
 
     /*
@@ -197,12 +200,6 @@ impl<'d, T: Instance> Adc<'d, T> {
                 // spin
             }
 
-            // Configure ADC
-            #[cfg(not(stm32g0))]
-            T::regs().cfgr().modify(|reg| reg.set_res(self.resolution.into()));
-            #[cfg(stm32g0)]
-            T::regs().cfgr1().modify(|reg| reg.set_res(self.resolution.into()));
-
             // Configure channel
             Self::set_channel_sample_time(pin.channel(), self.sample_time);
 
diff --git a/embassy-stm32/src/adc/v4.rs b/embassy-stm32/src/adc/v4.rs
index dc5f62d3c..750f3480f 100644
--- a/embassy-stm32/src/adc/v4.rs
+++ b/embassy-stm32/src/adc/v4.rs
@@ -227,7 +227,6 @@ impl Prescaler {
 
 pub struct Adc<'d, T: Instance> {
     sample_time: SampleTime,
-    resolution: Resolution,
     phantom: PhantomData<&'d mut T>,
 }
 
@@ -264,7 +263,6 @@ impl<'d, T: Instance + crate::rcc::RccPeripheral> Adc<'d, T> {
 
         let mut s = Self {
             sample_time: Default::default(),
-            resolution: Resolution::default(),
             phantom: PhantomData,
         };
         s.power_up(delay);
@@ -367,7 +365,9 @@ impl<'d, T: Instance + crate::rcc::RccPeripheral> Adc<'d, T> {
     }
 
     pub fn set_resolution(&mut self, resolution: Resolution) {
-        self.resolution = resolution;
+        unsafe {
+            T::regs().cfgr().modify(|reg| reg.set_res(resolution.into()));
+        }
     }
 
     /// Perform a single conversion.
@@ -408,9 +408,6 @@ impl<'d, T: Instance + crate::rcc::RccPeripheral> Adc<'d, T> {
     }
 
     unsafe fn read_channel(&mut self, channel: u8) -> u16 {
-        // Configure ADC
-        T::regs().cfgr().modify(|reg| reg.set_res(self.resolution.into()));
-
         // Configure channel
         Self::set_channel_sample_time(channel, self.sample_time);