PWM adc ADC not running simultaneously on ATmega8

#include<avr/io.h>
#include<avr/interrupt.h>
 
void adcinit()
{
    ADMUX &= ~(1 << REFS0);
    ADMUX &= ~(1 << REFS1); // Aref is selected, internal vref is disabled
    ADMUX &= ~(1 << MUX3);
    ADMUX &= ~(1 << MUX2);
    ADMUX &= ~(1 << MUX1);
    ADMUX &= ~(1 << MUX0);
 
    ADCSRA |= (1 << ADEN);  // enable the adc
    ADCSRA &= ~(1 << ADSC);
    ADCSRA &= ~(1 << ADFR);
    ADCSRA &= ~(1 << ADIF);
    ADCSRA &= ~(1 << ADIE);
    ADCSRA |= (1 << ADPS2);
    ADCSRA |= (1 << ADPS1);
    ADCSRA |= (1 << ADPS0); // division factor 128
 
    return;
}
 
unsigned int adcread(unsigned char ch)
{
    ADMUX = (ch & 0x07); // if all the pins in admux are zero no need to apply a bitwise or operation, while a masking is already done by a  bitwise and operation.
 
    ADCSRA |= (1 << ADSC);
 
    while( ADCSRA & ( 1 << ADSC )); // wait for conversion completes
 
    return ADC;
}
    
 
void msdelay(unsigned int itime)
{
    unsigned int i,j;
 
    for(i=0;i<itime;i++)
    {
        for(j=0;j<100;j++)
        {
        }
    }
    return;
}
 
void PWM_on()
{
    TCCR2 |= (1 << COM21);  // set pwm on non inverting mode
 
    TCCR2 |= (1 << WGM21) | (1 << WGM20);
    // set fast pwm mode
 
    TCCR2 |= (1 << CS20);
    // start the pwm with prescalar 1
    
    return;
}
 
 
int main()
{
    unsigned char duty=0;
    unsigned int feedback=0;
 
    DDRB=0xFF;
    DDRD=0xFF;
 
    adcinit();
    PWM_on();
 
    OCR2=128;
 
    while(1)
    {
        feedback=adcread(0);
 
        if(feedback<200)
        {
            duty++;
        }
 
        if(feedback>220)
        {
            duty--;
        }
 
        OCR2=duty;
 
        msdelay(500);
 
    }
    return 0;
}