Messages in this thread | | | Date | Tue, 19 Apr 2011 23:30:01 +0900 | Subject | SPI problem | From | "Murali K. Vemuri" <> |
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Hello there, I have a device which is Written_to/Read_from using SPI Bus.
I initialize the device like this:
static int __init myDEV_init(void) { return spi_register_driver(&myDEV_driver); } module_init(myDEV_init);
My myDEV_probe() function looks like this:
static int __devinit myDEV_probe(struct spi_device *spi) { ..... ..... /*when my CPU receives a particular IRQ, I have to do a spi_read() and do couple of spi_write(), I am using like this:*/ err = request_threaded_irq (MY_DEV_IRQ, NULL, myDEV_irq_thread, IRQF_TRIGGER_RISING, "MYDEV", NULL);
return 0; }
When the Interrupt is received by the CPU, myDEV_irq_thread is being called. However, in the ISR I have to do spi_read(). This is always returning "Timed out".
To verify if the device is not at all working, along with registering for the IRQ, I also created a char device through I did a IOCTL. The IOCTL command in turn does spi_read(). In this case spi_read() is successful.
Since it is necessary to do spi_read() in my ISR, I searched around and found some information that spi_read() is callable only from contexts that can sleep.
How can I make my ISR sleep? or is there any other way of doing this?
Any help is highly appreciated. Thanks & regards Murali
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