mfd: fix pcap irq bottom handler

Mask interrupts before servicing them and loop while pcap asserts the interrupt
line.

Signed-off-by: Daniel Ribeiro <drwyrm@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 27 insertions, 22 deletions

diff --git a/drivers/mfd/ezx-pcap.c b/drivers/mfd/ezx-pcap.c
index c5122024f05a..732664f238fe 100644
--- a/drivers/mfd/ezx-pcap.c
+++ b/drivers/mfd/ezx-pcap.c
@@ -17,6 +17,7 @@
 #include <linux/irq.h>
 #include <linux/mfd/ezx-pcap.h>
 #include <linux/spi/spi.h>
+#include <linux/gpio.h>
 
 #define PCAP_ADC_MAXQ           8
 struct pcap_adc_request {
@@ -155,34 +156,38 @@ static void pcap_isr_work(struct work_struct *work)
         u32 msr, isr, int_sel, service;
         int irq;
 
-        ezx_pcap_read(pcap, PCAP_REG_MSR, &msr);
-        ezx_pcap_read(pcap, PCAP_REG_ISR, &isr);
+        do {
+                ezx_pcap_read(pcap, PCAP_REG_MSR, &msr);
+                ezx_pcap_read(pcap, PCAP_REG_ISR, &isr);
 
-        /* We cant service/ack irqs that are assigned to port 2 */
-        if (!(pdata->config & PCAP_SECOND_PORT)) {
-                ezx_pcap_read(pcap, PCAP_REG_INT_SEL, &int_sel);
-                isr &= ~int_sel;
-        }
-        ezx_pcap_write(pcap, PCAP_REG_ISR, isr);
+                /* We cant service/ack irqs that are assigned to port 2 */
+                if (!(pdata->config & PCAP_SECOND_PORT)) {
+                        ezx_pcap_read(pcap, PCAP_REG_INT_SEL, &int_sel);
+                        isr &= ~int_sel;
+                }
 
-        local_irq_disable();
-        service = isr & ~msr;
+                ezx_pcap_write(pcap, PCAP_REG_MSR, isr | msr);
+                ezx_pcap_write(pcap, PCAP_REG_ISR, isr);
 
-        for (irq = pcap->irq_base; service; service >>= 1, irq++) {
-                if (service & 1) {
-                        struct irq_desc *desc = irq_to_desc(irq);
+                local_irq_disable();
+                service = isr & ~msr;
+                for (irq = pcap->irq_base; service; service >>= 1, irq++) {
+                        if (service & 1) {
+                                struct irq_desc *desc = irq_to_desc(irq);
 
-                        if (WARN(!desc, KERN_WARNING
-                                        "Invalid PCAP IRQ %d\n", irq))
-                                break;
+                                if (WARN(!desc, KERN_WARNING
+                                                "Invalid PCAP IRQ %d\n", irq))
+                                        break;
 
-                        if (desc->status & IRQ_DISABLED)
-                                note_interrupt(irq, desc, IRQ_NONE);
-                        else
-                                desc->handle_irq(irq, desc);
+                                if (desc->status & IRQ_DISABLED)
+                                        note_interrupt(irq, desc, IRQ_NONE);
+                                else
+                                        desc->handle_irq(irq, desc);
+                        }
                 }
-        }
-        local_irq_enable();
+                local_irq_enable();
+                ezx_pcap_write(pcap, PCAP_REG_MSR, pcap->msr);
+        } while (gpio_get_value(irq_to_gpio(pcap->spi->irq)));
 }
 
 static void pcap_irq_handler(unsigned int irq, struct irq_desc *desc)