On Wed, Sep 29, 2021 at 5:36 AM Brian Norris <[email protected]> wrote: > > In commit 43c2de1002d2, we moved most HW configuration to bind(), but we > didn't move the runtime PM management. Therefore, depending on initial > boot state, runtime-PM workqueue delays, and other timing factors, we > may disable our power domain in between the hardware configuration > (bind()) and when we enable the display. This can cause us to lose > hardware state and fail to configure our display. For example: > > dw-mipi-dsi-rockchip ff968000.mipi: failed to write command FIFO > panel-innolux-p079zca ff960000.mipi.0: failed to write command 0 > > or: > > dw-mipi-dsi-rockchip ff968000.mipi: failed to write command FIFO > panel-kingdisplay-kd097d04 ff960000.mipi.0: failed write init cmds: -110 > > We should match the runtime PM to the lifetime of the bind()/unbind() > cycle. > > Tested on Acer Chrometab 10 (RK3399 Gru-Scarlet), with panel drivers > built either as modules or built-in. > > Side notes: it seems one is more likely to see this problem when the > panel driver is built into the kernel. I've also seen this problem > bisect down to commits that simply changed Kconfig dependencies, because > it changed the order in which driver init functions were compiled into > the kernel, and therefore the ordering and timing of built-in device > probe. > > Fixes: 43c2de1002d2 ("drm/rockchip: dsi: move all lane config except LCDC mux > to bind()") > Link: > https://lore.kernel.org/linux-rockchip/[email protected]/ > Reported-by: <[email protected]> > Cc: <[email protected]> > Signed-off-by: Brian Norris <[email protected]> > Tested-by: Nícolas F. R. A. Prado <[email protected]>
Reviewed-by: Chen-Yu Tsai <[email protected]>
