Hi, I am going to add locking to the cx25840 module register reads and writes because I now have a case where a workqueue, a userpace, and/or the cx25840 firmware loading workqueue could contend for access to the CX2584x or equivalent device. I have identiifed the following drivers that actually use this module: cx231xx, pvrusb2, ivtv, cx23885 Now here's where I need help, since I don't understand the USB stuff too well and there's a lot of code to audit: Do any of these modules call the cx25840 routines with either: a. call the cx25840 module subdev functions with a spinlock held ? or b. call the cx25840 module subdev functions from an interrupt context: i.e. a hard irq or tasklet ? or c. bypass the normal cx25840_read/write calls with direct I2C access to the client address of 0x44 (0x88 >> 1) ? Any definitive confirmation anyone can give on any of these drivers would be helpful and would save me some time. For the cx23885 driver I think these are the answers: a. probably not b. probably not c. yes but I have to double check. I can probably audit the ivtv driver on my own. I understand it's structure, but it's a big driver and will take time to check, if no one knows off hand. The pvrusb2 and cx231xx will be a little harder for me. They aren't terribly large, but I don't understand USB device "interrupt" contexts. TIA. Regards, Andy -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
