[U-Boot] [PATCH] video: ipuv3_fb: skip IPU shutdown if IPU was not enabled before
Anatolij Gustschin
agust at denx.de
Mon Aug 28 18:23:12 UTC 2017
Hi Stefano,
On Mon, 28 Aug 2017 18:54:39 +0200
Stefano Babic sbabic at denx.de wrote:
...
> > + /*
> > + * Check if IPU clock was enabled before. Won't access
> > + * IPU registers if clock is not enabled.
> > + */
> > + reg = readl(&mxc_ccm->CCGR3);
> > + if ((reg & MXC_CCM_CCGR3_IPU1_IPU_MASK) == 0)
> > + return;
> >
>
> It looks to me quite weak to simply check if clock is gated. On some
> board clock is gated even if IPU is not active. Do you have a way
> reading inside IPU itself ? Then we can better decide if it was really
> acrive. For example, checking if ipu_enable_channel() was called (and
> DMA registers are set).
we cannot access IPU registers when IPU clock is disabled (register
access will hang the CPU).
Thanks,
Anatolij
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