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From: Jan K. <jan...@si...> - 2010-10-07 09:22:46
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Am 07.10.2010 11:13, Gilles Chanteperdrix wrote: > Jan Kiszka wrote: >> Am 04.10.2010 22:13, Edward Hoffman wrote: >>> I am attempting to port the Broadcom tg3 NetXtreme linux driver to >>> rtnet. >> >> Your port will be welcome! >> >>> The Broadcom driver internally utilizes >>> spin_lock_bh/spin_unlock_bh to disable/enable software interrupts. >>> There is no rtdm lock equivalent. >>> I believe that software interrupts are used by the driver for the >>> following reasons: >>> 1. To allow for simultaneous DMA read write operations >>> 2. To use shared local variables in a critical section of the driver. >>> 3. To receive changes to settings variables in realtime from the >>> userpace Nextreme utilities. (not sure about this one). >>> >>> What RTDM lock functions should I use to substitute for >>> spin_lock_bh/spin_unlock_bh? Should I substitute >>> rtdm_lock_get_irqsave/rtdm_lock_put_irqrestore? Or does rtdm need to ne >>> extended for softirqs used internally by the driver? >>> >>> I looked through the other device drivers and could not detect the >>> correct substitute. >> >> As RTDM provides no abstraction of bottom-halves, there are also no >> specific locking services to disable them. You have to use IRQ-disabling >> services unless you are in IRQ context. > > Maybe if you want to only exclude the driver's irq, you may only disable > the irq line at IC level, with rtdm_irq_disable? Usually discouraged due to potentially slow line-disabling services and the breakage this will cause when the line is shared. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux |
