> -----Original Message----- > From: Cousson, Benoit > Sent: Wednesday, August 04, 2010 3:38 PM > To: G, Manjunath Kondaiah > Cc: Kevin Hilman; linux-omap@xxxxxxxxxxxxxxx; Paul Walmsley; Tony > Lindgren; Sawant, Anand; Shilimkar, Santosh; Nayak, Rajendra; Basak, > Partha; Varadarajan, Charulatha > Subject: Re: [PATCH 04/11] OMAP3: DMA: HWMOD: Add hwmod data structures > > On 8/4/2010 2:35 AM, G, Manjunath Kondaiah wrote: > > Kevin, > > > >> From: Kevin Hilman [mailto:khilman@xxxxxxxxxxxxxxxxxxx] > >> Sent: Wednesday, August 04, 2010 3:27 AM > >> > >> Manjunatha GK<manjugk@xxxxxx> writes: > >> > >>> This patch adds OMAP3 DMA hwmod structures. > >>> > >>> Signed-off-by: Manjunatha GK<manjugk@xxxxxx> > >> > >> [...] > >> > >>> +static struct omap_hwmod omap3xxx_dma_system_hwmod = { > >>> + .name = "dma", > >>> + .class =&omap3xxx_dma_hwmod_class, > >>> + .mpu_irqs = omap3xxx_dma_system_irqs, > >>> + .mpu_irqs_cnt = ARRAY_SIZE(omap3xxx_dma_system_irqs), > >>> + .main_clk = "l3_div_ck", > >>> + .prcm = { > >>> + .omap2 = { > >>> + /* .clkctrl_reg = NULL, */ > >>> + }, > >>> + }, > >> > >> Has this been tested? Without valid fields here the hwmod > >> will never be > >> enabled. > > > > This patch series has been tested on both omap3 and omap4. I didn't find > > any entries for DMA module in prcm-common.h(for assigning .module_bit > etc) > > hence I commented this for clarification. > > There is no explicit PRCM control for the SDMA. You can just access the > standby status and change the sysconfig idle and standby settings. > It uses the L3 interface clock as functional clock. > You should still use HWMOD_NO_IDLEST status to prevent the enable to > crash. > > In your case, I think that you are probably never explicitly enabling or > disabling the dma device due to the library kind of API and the fact > that the HW is managing is automatically, isn't it? > > We had the same kind of discussion for the hwspinlock. Since these IPs > are using interface clock as a functional clock, there is no need to > explicitly enable them. But we should, otherwise we have no way to track > the usage of this IP and potentially to enable the power domain that > contains these IP. > > Each time a dma channel is requested, you should call the > pm_runtime_get, and pm_runtime_put() when the channel is not needed > anymore. > Request call can get called on multiple channels. So at the time of request a channel, other channels might be already in use. So logically " pm_runtime_put" should only be done if reserved channels are 0 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
