Re: [PATCH 1/1] i2c: rcar: handle RXDMA HW behaviour on Gen3

2018-07-24 Thread Wolfram Sang
On Mon, Jul 23, 2018 at 07:55:22PM +0200, Wolfram Sang wrote: > On Thu, Jun 28, 2018 at 10:45:38PM +0200, Wolfram Sang wrote: > > On Gen3, we can only do RXDMA once per transfer reliably. For that, we > > must reset the device, then we can have RXDMA once. This patch > > implements this. When

Re: [PATCH 1/1] i2c: rcar: handle RXDMA HW behaviour on Gen3

2018-07-23 Thread Wolfram Sang
On Thu, Jun 28, 2018 at 10:45:38PM +0200, Wolfram Sang wrote: > On Gen3, we can only do RXDMA once per transfer reliably. For that, we > must reset the device, then we can have RXDMA once. This patch > implements this. When there is no reset controller or the reset fails, > RXDMA will be blocked

Re: [PATCH 1/1] i2c: rcar: handle RXDMA HW behaviour on Gen3

2018-07-23 Thread Wolfram Sang
On Fri, Jun 29, 2018 at 09:54:04AM +0200, Wolfram Sang wrote: > > > > + /* Gen3 needs a reset before allowing RXDMA once */ > > > + if (priv->devtype == I2C_RCAR_GEN3) { > > > > So on R-Car Gen3 the device is always reset, even if no reads will be done? > > Or is that something you

Re: [PATCH 1/1] i2c: rcar: handle RXDMA HW behaviour on Gen3

2018-06-29 Thread Wolfram Sang
> > + /* Gen3 needs a reset before allowing RXDMA once */ > > + if (priv->devtype == I2C_RCAR_GEN3) { > > So on R-Car Gen3 the device is always reset, even if no reads will be done? > Or is that something you cannot check for at this point? You got a point. I copied the behaviour

Re: [PATCH 1/1] i2c: rcar: handle RXDMA HW behaviour on Gen3

2018-06-29 Thread Geert Uytterhoeven
Hi Wolfram, On Thu, Jun 28, 2018 at 10:45 PM Wolfram Sang wrote: > On Gen3, we can only do RXDMA once per transfer reliably. For that, we > must reset the device, then we can have RXDMA once. This patch > implements this. When there is no reset controller or the reset fails, > RXDMA will be

[PATCH 1/1] i2c: rcar: handle RXDMA HW behaviour on Gen3

2018-06-28 Thread Wolfram Sang
On Gen3, we can only do RXDMA once per transfer reliably. For that, we must reset the device, then we can have RXDMA once. This patch implements this. When there is no reset controller or the reset fails, RXDMA will be blocked completely. Otherwise, it will be disabled after the first RXDMA