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List:       dmaengine
Subject:    Re: [PATCH] dmaengine: cppi41: Fix issue with musb and ftdi uart
From:       Tony Lindgren <tony () atomide ! com>
Date:       2019-10-23 15:27:55
Message-ID: 20191023152755.GK5610 () atomide ! com
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* Vinod Koul <vkoul@kernel.org> [191023 04:54]:
> Hi Tony,
> 
> On 22-10-19, 07:55, Tony Lindgren wrote:
> 
> Patch subject should reflect the patch changes not the fix. The patch
> title here is not telling me anything about the change below. Pls
> consider updating the title.

Sure, I'll resend with updated description using:

dmaengine: cppi41: Fix cppi41_dma_prep_slave_sg() when idle

> > The first dma call done by musb_ep_program() must wait if cppi41 is PM
> > runtime suspended. Otherwise musb_ep_program() continues with other
> > non-dma packets before the DMA transfer is started causing at least ftdi
> > uarts to fail to receive data.
> > 
> > Let's fix the issue by waking up cppi41 with PM runtime calls added to
> > cppi41_dma_prep_slave_sg() and return NULL if still idled. This way we
> > have musb_ep_program() continue with PIO until cppi41 is awake.
> > 
> > Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support")
> 
> Cc stable?

Yes please.

Regards,

Tony
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