On Wed, 2019-07-31 at 10:45 +0800, Fuqian Huang wrote: > In drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c, > amdgpu_ih_process calls DRM_DEBUG which calls drm_dbg and > finally calls printk. > As amdgpu_ih_process is called from an interrupt handler, > and interrupt handler should be short as possible. > > As printk may lead to bogging down the system or can even > create a live lock. printk should not be used in IRQ context. > Instead, trace_printk is recommended. > Link: https://lwn.net/Articles/365835 [] > diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c [] > @@ -236,7 +236,7 @@ void drm_dbg(unsigned int category, const char *format, ...) > vaf.fmt = format; > vaf.va = &args; > > - printk(KERN_DEBUG "[" DRM_NAME ":%ps] %pV", > + trace_printk(KERN_DEBUG "[" DRM_NAME ":%ps] %pV", > __builtin_return_address(0), &vaf); > > va_end(args); This makes all 4000+ drm_dbg/DRM_DEBUG uses emit a trace_printk. I suggest instead you make only the interrupt uses use a different function and not drm_dbg. Or maybe add an in_interrupt() check like if (in_interrupt()) printk(KERN_DEBUG etc...) else trace_printk(etc...) _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
