Re: [PATCH v2 7/8] drm/i915: Keep the AKSV details in intel_dp_hdcp_write_an_aksv()

Ville Syrjälä
2018-02-23T13:46:39Z

On Fri, Feb 23, 2018 at 04:40:42PM +0530, Ramalingam C wrote:
> This is really making it cleaner.
>
> Reviewed-by: Ramalingam C <ramalingam.c@intel.com>
>
>
>
> On Friday 23 February 2018 02:57 AM, Ville Syrjala wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >
> > Let's try to keep the details on the AKSV stuff concentrated
> > in one place. So move the control bit and +5 data size handling
> > there.
> >
> > v2: Increase txbuf[] to include the payload which intel_dp_aux_xfer()
> > will still load into the registers even though the hardware
> > will ignore it
> >
> > Cc: Sean Paul <seanpaul@chromium.org>
> > Cc: Ramalingam C <ramalingam.c@intel.com>
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> > drivers/gpu/drm/i915/intel_dp.c | 42 +++++++++++++----------------------------
> > 1 file changed, 13 insertions(+), 29 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > index 217cc6aee477..0d699d230b77 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -1059,29 +1059,11 @@ static uint32_t skl_get_aux_send_ctl(struct intel_dp *intel_dp,
> > DP_AUX_CH_CTL_SYNC_PULSE_SKL(32);
> > }
> >
> > -static uint32_t intel_dp_get_aux_send_ctl(struct intel_dp *intel_dp,
> > - bool has_aux_irq,
> > - int send_bytes,
> > - uint32_t aux_clock_divider,
> > - bool aksv_write)
> > -{
> > - uint32_t val = 0;
> > -
> > - if (aksv_write) {
> > - send_bytes += 5;
> > - val |= DP_AUX_CH_CTL_AUX_AKSV_SELECT;
> > - }
> > -
> > - return val | intel_dp->get_aux_send_ctl(intel_dp,
> > - has_aux_irq,
> > - send_bytes,
> > - aux_clock_divider);
> > -}
> > -
> > static int
> > intel_dp_aux_xfer(struct intel_dp *intel_dp,
> > const uint8_t *send, int send_bytes,
> > - uint8_t *recv, int recv_size, bool aksv_write)
> > + uint8_t *recv, int recv_size,
> > + u32 aux_send_ctl_flags)
> > {
> > struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
> > struct drm_i915_private *dev_priv =
> > @@ -1145,11 +1127,12 @@ intel_dp_aux_xfer(struct intel_dp *intel_dp,
> > }
> >
> > while ((aux_clock_divider = intel_dp->get_aux_clock_divider(intel_dp, clock++))) {
> > - u32 send_ctl = intel_dp_get_aux_send_ctl(intel_dp,
> > - has_aux_irq,
> > - send_bytes,
> > - aux_clock_divider,
> > - aksv_write);
> > + u32 send_ctl = intel_dp->get_aux_send_ctl(intel_dp,
> > + has_aux_irq,
> > + send_bytes,
> > + aux_clock_divider);
> > +
> > + send_ctl |= aux_send_ctl_flags;
> >
> > /* Must try at least 3 times according to DP spec */
> > for (try = 0; try < 5; try++) {
> > @@ -1287,7 +1270,7 @@ intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
> > memcpy(txbuf + HEADER_SIZE, msg->buffer, msg->size);
> >
> > ret = intel_dp_aux_xfer(intel_dp, txbuf, txsize,
> > - rxbuf, rxsize, false);
> > + rxbuf, rxsize, 0);
> > if (ret > 0) {
> > msg->reply = rxbuf[0] >> 4;
> >
> > @@ -1310,7 +1293,7 @@ intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
> > return -E2BIG;
> >
> > ret = intel_dp_aux_xfer(intel_dp, txbuf, txsize,
> > - rxbuf, rxsize, false);
> > + rxbuf, rxsize, 0);
> > if (ret > 0) {
> > msg->reply = rxbuf[0] >> 4;
> > /*
> > @@ -5085,7 +5068,7 @@ int intel_dp_hdcp_write_an_aksv(struct intel_digital_port *intel_dig_port,
> > u8 *an)
> > {
> > struct intel_dp *intel_dp = enc_to_intel_dp(&intel_dig_port->base.base);
> > - uint8_t txbuf[4], rxbuf[2], reply = 0;
> > + uint8_t txbuf[4+5] = {}, rxbuf[2], reply = 0;
> You might want to use the macros for size of txbuf as  HEADER_SIZE +
> DRM_HDCP_KSV_LEN, as it is done in the next patch.

As the original code was using a bare 5 I figured I'll keep using it here
as well to make it easier to see what's moving where.

> --Ram
> > ssize_t dpcd_ret;
> > int ret;
> >
> > @@ -5110,7 +5093,8 @@ int intel_dp_hdcp_write_an_aksv(struct intel_digital_port *intel_dig_port,
> > txbuf[3] = DRM_HDCP_KSV_LEN - 1;
> >
> > ret = intel_dp_aux_xfer(intel_dp, txbuf, sizeof(txbuf),
> > - rxbuf, sizeof(rxbuf), true);
> > + rxbuf, sizeof(rxbuf),
> > + DP_AUX_CH_CTL_AUX_AKSV_SELECT);
> > if (ret < 0) {
> > DRM_ERROR("Write Aksv over DP/AUX failed (%d)\n", ret);
> > return ret;

--
Ville Syrjälä
Intel OTC