On Mon, 21 Mar 2016 15:17:37 +0100, Yang, Libin wrote: > > > > -----Original Message----- > > From: Takashi Iwai [mailto:tiwai@xxxxxxx] > > Sent: Monday, March 21, 2016 6:45 PM > > To: libin.yang@xxxxxxxxxxxxxxx > > Cc: intel-gfx@xxxxxxxxxxxxxxxxxxxxx; conselvan2@xxxxxxxxx; > > jani.nikula@xxxxxxxxxxxxxxx; ville.syrjala@xxxxxxxxxxxxxxx; Vetter, Daniel; > > tiwai@xxxxxxx; Yang, Libin > > Subject: Re: [PATCH] drm/i915: intel_audio clear eld buf when > > disconnecting monitor > > > > On Mon, 21 Mar 2016 06:03:29 +0100, > > libin.yang@xxxxxxxxxxxxxxx wrote: > > > > > > From: Libin Yang <libin.yang@xxxxxxxxxxxxxxx> > > > > > > When disconnecting monitor, dev_priv->dig_port_map[port] > > > will be set NULL, which causes eld will not be updated in > > > i915_audio_component_get_eld(). > > > > > > This patch clears the eld buf when dev_priv->dig_port_map[port] > > > is NULL. > > > > > > Signed-off-by: Libin Yang <libin.yang@xxxxxxxxxxxxxxx> > > > > While this isn't certainly bad, I don't think it's mandatory. The > > function returns zero, i.e. no data is copied. So the caller > > shouldn't expect that the buffer is cleared in this case. > > Without the patch, we find when unplug the monitor, the eld info > will not be updated. The means the eld info in the procfs still remains > the old info after the monitor is disconnected. Well, it's not about zero-clear but rather because the function returns an error (-EINVAL), and the caller takes it too seriously. Upon receiving an error code, the HDA driver doesn't read ELD at all, so it won't help even if you do zero-clear there. The alternative fix patch is below. Takashi -- 8< -- From: Takashi Iwai <tiwai@xxxxxxx> Subject: [PATCH] drm/i915: Don't handle NULL encoder as an error in get_eld notifier Since we fixed the dig_port_map[] assignment rather in a dynamic manner by the commit [2f791908a70e: drm/i915: Fix bogus dig_port_map[] assignment for pre-HSW], the NULL encoder is no longer an error but it just indicates that the unconnected state. However, in the caller (HD-audio) side, it's taken as a serious error, and it leads to the missing update of ELD after unplugging. As a fix, this patch changes get_eld notifier to return zero and initialize the enabled argument properly as false when no encoder is mapped for indicating the unconnected state. Fixes: 2f791908a70e ('drm/i915: Fix bogus dig_port_map[] assignment for pre-HSW') Cc: <stable@xxxxxxxxxxxxxxx> # v4.5 Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> --- drivers/gpu/drm/i915/intel_audio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c index 31f6d212fb1b..63493a63500e 100644 --- a/drivers/gpu/drm/i915/intel_audio.c +++ b/drivers/gpu/drm/i915/intel_audio.c @@ -717,13 +717,13 @@ static int i915_audio_component_get_eld(struct device *dev, int port, struct intel_encoder *intel_encoder; struct intel_digital_port *intel_dig_port; const u8 *eld; - int ret = -EINVAL; + int ret = 0; + *enabled = false; mutex_lock(&dev_priv->av_mutex); intel_encoder = dev_priv->dig_port_map[port]; /* intel_encoder might be NULL for DP MST */ if (intel_encoder) { - ret = 0; intel_dig_port = enc_to_dig_port(&intel_encoder->base); *enabled = intel_dig_port->audio_connector != NULL; if (*enabled) { -- 2.7.4 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
