On 28/06/16 17:56, Dave Gordon wrote:
Part spin-wait, part sleep-wait. Plus one example of where it might be used.Signed-off-by: Dave Gordon <david.s.gor...@intel.com> --- drivers/gpu/drm/i915/i915_guc_submission.c | 2 +- drivers/gpu/drm/i915/intel_drv.h | 10 ++++++++++ 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c index 355b647..ff99910 100644 --- a/drivers/gpu/drm/i915/i915_guc_submission.c +++ b/drivers/gpu/drm/i915/i915_guc_submission.c @@ -98,7 +98,7 @@ static int host2guc_action(struct intel_guc *guc, u32 *data, u32 len) I915_WRITE(HOST2GUC_INTERRUPT, HOST2GUC_TRIGGER); /* No HOST2GUC command should take longer than 10ms */ - ret = wait_for_atomic(host2guc_action_response(dev_priv, &status), 10); + ret = wait_for_hybrid(host2guc_action_response(dev_priv, &status), 10, 10); if (status != GUC2HOST_STATUS_SUCCESS) { /* * Either the GuC explicitly returned an error (which diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 3156d8d..096e07c 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -103,6 +103,16 @@ #define wait_for_atomic(COND, MS) _wait_for_atomic((COND), (MS) * 1000) #define wait_for_atomic_us(COND, US) _wait_for_atomic((COND), (US)) +/* Hybrid wait: + * first spin-wait for up to <US> microseconds, + * if <COND> still not true, sleep-wait for MS milliseconds + */ +#define wait_for_hybrid(COND, US, MS) ({ \ + int ret__ = wait_for_atomic_us(COND, US); \ + if (ret__) ret__ = wait_for(COND, MS); \ + ret__; \ + }) + #define KHz(x) (1000 * (x)) #define MHz(x) KHz(1000 * (x))
Wouldn't harm anything if you know typical GuC response time is under 10us and 10ms timeout is backed with some documentation.
Another idea could be a wait_for variant which takes those values, so typical and maximum response time, and then it could decide statically in the macro what to do.
Regards, Tvrtko _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
