Message ID | 20210323025501.1568039-1-quanyang.wang@windriver.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | [V2] drm: xlnx: zynqmp: release reset to DP controller before accessing DP registers | expand |
Hi Quanyang, Thank you for the patch. On Tue, Mar 23, 2021 at 10:55:01AM +0800, quanyang.wang@windriver.com wrote: > From: Quanyang Wang <quanyang.wang@windriver.com> > > When insmod zynqmp-dpsub.ko after rmmod it, system will hang with the > error log as below: > > root@xilinx-zynqmp:~# insmod zynqmp-dpsub.ko > [ 88.391289] [drm] Initialized zynqmp-dpsub 1.0.0 20130509 for fd4a0000.display on minor 0 > [ 88.529906] Console: switching to colour frame buffer device 128x48 > [ 88.549402] zynqmp-dpsub fd4a0000.display: [drm] fb0: zynqmp-dpsubdrm frame buffer device > [ 88.571624] zynqmp-dpsub fd4a0000.display: ZynqMP DisplayPort Subsystem driver probed > root@xilinx-zynqmp:~# rmmod zynqmp_dpsub > [ 94.023404] Console: switching to colour dummy device 80x25 > root@xilinx-zynqmp:~# insmod zynqmp-dpsub.ko > <hang here> > > This is because that in zynqmp_dp_probe it tries to access some DP > registers while the DP controller is still in the reset state. When > running "rmmod zynqmp_dpsub", zynqmp_dp_reset(dp, true) in > zynqmp_dp_phy_exit is called to force the DP controller into the reset > state. Then insmod will call zynqmp_dp_probe to program the DP registers, > but at this moment the DP controller hasn't been brought out of the reset > state yet since the function zynqmp_dp_reset(dp, false) is called later and > this will result the system hang. > > Releasing the reset to DP controller before any read/write operation to it > will fix this issue. And for symmetry, move zynqmp_dp_reset() call from > zynqmp_dp_phy_exit() to zynqmp_dp_remove(). > > Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > > V2: > According to Laurent's comments: > - add zynqmp_dp_reset(dp, true) in error path in zynqmp_dp_probe > - move the zynqmp_dp_reset() call from zynqmp_dp_phy_exit() to zynqmp_dp_remove() > > --- > drivers/gpu/drm/xlnx/zynqmp_dp.c | 22 ++++++++++++---------- > 1 file changed, 12 insertions(+), 10 deletions(-) > > diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c > index 99158ee67d02..337adf0769ad 100644 > --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c > +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c > @@ -402,10 +402,6 @@ static int zynqmp_dp_phy_init(struct zynqmp_dp *dp) > } > } > > - ret = zynqmp_dp_reset(dp, false); > - if (ret < 0) > - return ret; > - > zynqmp_dp_clr(dp, ZYNQMP_DP_PHY_RESET, ZYNQMP_DP_PHY_RESET_ALL_RESET); > > /* > @@ -441,8 +437,6 @@ static void zynqmp_dp_phy_exit(struct zynqmp_dp *dp) > ret); > } > > - zynqmp_dp_reset(dp, true); > - > for (i = 0; i < dp->num_lanes; i++) { > ret = phy_exit(dp->phy[i]); > if (ret) > @@ -1682,9 +1676,13 @@ int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub, struct drm_device *drm) > return PTR_ERR(dp->reset); > } > > + ret = zynqmp_dp_reset(dp, false); > + if (ret < 0) > + return ret; > + > ret = zynqmp_dp_phy_probe(dp); > if (ret) > - return ret; > + goto err_reset; > > /* Initialize the hardware. */ > zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN, > @@ -1696,7 +1694,7 @@ int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub, struct drm_device *drm) > > ret = zynqmp_dp_phy_init(dp); > if (ret) > - return ret; > + goto err_reset; > > zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 1); > > @@ -1708,15 +1706,18 @@ int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub, struct drm_device *drm) > zynqmp_dp_irq_handler, IRQF_ONESHOT, > dev_name(dp->dev), dp); > if (ret < 0) > - goto error; > + goto err_phy_exit; > > dev_dbg(dp->dev, "ZynqMP DisplayPort Tx probed with %u lanes\n", > dp->num_lanes); > > return 0; > > -error: > +err_phy_exit: > zynqmp_dp_phy_exit(dp); > +err_reset: > + zynqmp_dp_reset(dp, true); > + > return ret; > } > > @@ -1734,4 +1735,5 @@ void zynqmp_dp_remove(struct zynqmp_dpsub *dpsub) > zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, 0xffffffff); > > zynqmp_dp_phy_exit(dp); > + zynqmp_dp_reset(dp, true); > }
Hi, st 24. 3. 2021 v 4:15 odesÃlatel Laurent Pinchart <laurent.pinchart@ideasonboard.com> napsal: > > Hi Quanyang, > > Thank you for the patch. > > On Tue, Mar 23, 2021 at 10:55:01AM +0800, quanyang.wang@windriver.com wrote: > > From: Quanyang Wang <quanyang.wang@windriver.com> > > > > When insmod zynqmp-dpsub.ko after rmmod it, system will hang with the > > error log as below: > > > > root@xilinx-zynqmp:~# insmod zynqmp-dpsub.ko > > [ 88.391289] [drm] Initialized zynqmp-dpsub 1.0.0 20130509 for fd4a0000.display on minor 0 > > [ 88.529906] Console: switching to colour frame buffer device 128x48 > > [ 88.549402] zynqmp-dpsub fd4a0000.display: [drm] fb0: zynqmp-dpsubdrm frame buffer device > > [ 88.571624] zynqmp-dpsub fd4a0000.display: ZynqMP DisplayPort Subsystem driver probed > > root@xilinx-zynqmp:~# rmmod zynqmp_dpsub > > [ 94.023404] Console: switching to colour dummy device 80x25 > > root@xilinx-zynqmp:~# insmod zynqmp-dpsub.ko > > <hang here> > > > > This is because that in zynqmp_dp_probe it tries to access some DP > > registers while the DP controller is still in the reset state. When > > running "rmmod zynqmp_dpsub", zynqmp_dp_reset(dp, true) in > > zynqmp_dp_phy_exit is called to force the DP controller into the reset > > state. Then insmod will call zynqmp_dp_probe to program the DP registers, > > but at this moment the DP controller hasn't been brought out of the reset > > state yet since the function zynqmp_dp_reset(dp, false) is called later and > > this will result the system hang. > > > > Releasing the reset to DP controller before any read/write operation to it > > will fix this issue. And for symmetry, move zynqmp_dp_reset() call from > > zynqmp_dp_phy_exit() to zynqmp_dp_remove(). > > > > Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com> > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Can someone pick this patch? Thanks, Michal
Hi Michale, On Fri, Aug 06, 2021 at 12:37:07PM +0200, Michal Simek wrote: > st 24. 3. 2021 v 4:15 odesÃlatel Laurent Pinchart napsal: > > On Tue, Mar 23, 2021 at 10:55:01AM +0800, quanyang.wang@windriver.com wrote: > > > From: Quanyang Wang <quanyang.wang@windriver.com> > > > > > > When insmod zynqmp-dpsub.ko after rmmod it, system will hang with the > > > error log as below: > > > > > > root@xilinx-zynqmp:~# insmod zynqmp-dpsub.ko > > > [ 88.391289] [drm] Initialized zynqmp-dpsub 1.0.0 20130509 for fd4a0000.display on minor 0 > > > [ 88.529906] Console: switching to colour frame buffer device 128x48 > > > [ 88.549402] zynqmp-dpsub fd4a0000.display: [drm] fb0: zynqmp-dpsubdrm frame buffer device > > > [ 88.571624] zynqmp-dpsub fd4a0000.display: ZynqMP DisplayPort Subsystem driver probed > > > root@xilinx-zynqmp:~# rmmod zynqmp_dpsub > > > [ 94.023404] Console: switching to colour dummy device 80x25 > > > root@xilinx-zynqmp:~# insmod zynqmp-dpsub.ko > > > <hang here> > > > > > > This is because that in zynqmp_dp_probe it tries to access some DP > > > registers while the DP controller is still in the reset state. When > > > running "rmmod zynqmp_dpsub", zynqmp_dp_reset(dp, true) in > > > zynqmp_dp_phy_exit is called to force the DP controller into the reset > > > state. Then insmod will call zynqmp_dp_probe to program the DP registers, > > > but at this moment the DP controller hasn't been brought out of the reset > > > state yet since the function zynqmp_dp_reset(dp, false) is called later and > > > this will result the system hang. > > > > > > Releasing the reset to DP controller before any read/write operation to it > > > will fix this issue. And for symmetry, move zynqmp_dp_reset() call from > > > zynqmp_dp_phy_exit() to zynqmp_dp_remove(). > > > > > > Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com> > > > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > > Can someone pick this patch? I have it in my tree with a set of other changes, I intend to send a pull request today.
diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c index 99158ee67d02..337adf0769ad 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c @@ -402,10 +402,6 @@ static int zynqmp_dp_phy_init(struct zynqmp_dp *dp) } } - ret = zynqmp_dp_reset(dp, false); - if (ret < 0) - return ret; - zynqmp_dp_clr(dp, ZYNQMP_DP_PHY_RESET, ZYNQMP_DP_PHY_RESET_ALL_RESET); /* @@ -441,8 +437,6 @@ static void zynqmp_dp_phy_exit(struct zynqmp_dp *dp) ret); } - zynqmp_dp_reset(dp, true); - for (i = 0; i < dp->num_lanes; i++) { ret = phy_exit(dp->phy[i]); if (ret) @@ -1682,9 +1676,13 @@ int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub, struct drm_device *drm) return PTR_ERR(dp->reset); } + ret = zynqmp_dp_reset(dp, false); + if (ret < 0) + return ret; + ret = zynqmp_dp_phy_probe(dp); if (ret) - return ret; + goto err_reset; /* Initialize the hardware. */ zynqmp_dp_write(dp, ZYNQMP_DP_TX_PHY_POWER_DOWN, @@ -1696,7 +1694,7 @@ int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub, struct drm_device *drm) ret = zynqmp_dp_phy_init(dp); if (ret) - return ret; + goto err_reset; zynqmp_dp_write(dp, ZYNQMP_DP_TRANSMITTER_ENABLE, 1); @@ -1708,15 +1706,18 @@ int zynqmp_dp_probe(struct zynqmp_dpsub *dpsub, struct drm_device *drm) zynqmp_dp_irq_handler, IRQF_ONESHOT, dev_name(dp->dev), dp); if (ret < 0) - goto error; + goto err_phy_exit; dev_dbg(dp->dev, "ZynqMP DisplayPort Tx probed with %u lanes\n", dp->num_lanes); return 0; -error: +err_phy_exit: zynqmp_dp_phy_exit(dp); +err_reset: + zynqmp_dp_reset(dp, true); + return ret; } @@ -1734,4 +1735,5 @@ void zynqmp_dp_remove(struct zynqmp_dpsub *dpsub) zynqmp_dp_write(dp, ZYNQMP_DP_INT_DS, 0xffffffff); zynqmp_dp_phy_exit(dp); + zynqmp_dp_reset(dp, true); }