From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B11C9C433EF for ; Thu, 5 May 2022 11:28:02 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 113E610EBC6; Thu, 5 May 2022 11:28:02 +0000 (UTC) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8DD7010EBC6 for ; Thu, 5 May 2022 11:28:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1651750080; x=1683286080; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=f2S4u6+UXeBNIuI1J+kCaTv+/rjRsC1En7ZqgAKY3RE=; b=h2fiBYLGKzBG8BviGtAPMdwvYIEJa+q095FU1GJNYR/RCzfUpkmZRHN6 CEqby7YLz9FtZF6uC90SG9zsXPUW58jTsEIZxzdCsm8N795kFJRtugqQm 9Nn2ZAk4D+QMGy1qRRtf6bfZvNlJk7KUR1cflOtqwPdzUYoQgBjA8sivx dPaZK0dqpI6YrT0/XxCA7D1rKae4ilULAeD6MP/3Fy2Bd8yzFwBqrNzc0 UN44DHxUzs3JRZdmvpeIL5hc8958U4SOLxfoKyX4elvMg7HSDZS5jAq8j n/tg5QRepYWou4Xvw1gmcIs5089/6Shn+yp6YtwW1BP4ONx3T8vqKr5KH g==; X-IronPort-AV: E=McAfee;i="6400,9594,10337"; a="354514394" X-IronPort-AV: E=Sophos;i="5.91,201,1647327600"; d="scan'208";a="354514394" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 May 2022 04:27:59 -0700 X-IronPort-AV: E=Sophos;i="5.91,201,1647327600"; d="scan'208";a="563199010" Received: from mstepka-mobl1.ger.corp.intel.com (HELO localhost) ([10.249.134.211]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 May 2022 04:27:56 -0700 From: Jani Nikula To: Tvrtko Ursulin , intel-gfx@lists.freedesktop.org In-Reply-To: <0854f6c3-8cca-da61-6370-60820dd4e392@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20220504183716.987793-1-jani.nikula@intel.com> <20220504183716.987793-3-jani.nikula@intel.com> <0854f6c3-8cca-da61-6370-60820dd4e392@linux.intel.com> Date: Thu, 05 May 2022 14:27:52 +0300 Message-ID: <87mtfwkymf.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Intel-gfx] [PATCH 3/3] drm/i915/display: stop using BUG() X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Thu, 05 May 2022, Tvrtko Ursulin wrote: > On 04/05/2022 19:37, Jani Nikula wrote: >> Avoid bringing the entire machine down even if there's a bug that >> shouldn't happen, but won't corrupt the system either. Log them loudly >> and limp on. >> >> Cc: Tvrtko Ursulin >> Signed-off-by: Jani Nikula >> --- >> drivers/gpu/drm/i915/display/intel_ddi.c | 11 ++++++----- >> drivers/gpu/drm/i915/display/intel_display.c | 19 +++++++++++-------- >> .../drm/i915/display/intel_display_types.h | 15 +++++++++------ >> 3 files changed, 26 insertions(+), 19 deletions(-) >> >> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c >> index 9e6fa59eabba..52cf6fb9994a 100644 >> --- a/drivers/gpu/drm/i915/display/intel_ddi.c >> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c >> @@ -455,6 +455,9 @@ intel_ddi_transcoder_func_reg_val_get(struct intel_encoder *encoder, >> temp |= TRANS_DDI_SELECT_PORT(port); >> >> switch (crtc_state->pipe_bpp) { >> + default: >> + MISSING_CASE(crtc_state->pipe_bpp); >> + fallthrough; >> case 18: >> temp |= TRANS_DDI_BPC_6; >> break; > > No idea of how this "limp" would look in practice and if it is safe. Worst case it's a black screen I think, but that's infinitely better than bringing the entire box down. > Same approach taken elsewhere in the patch so I'm afraid someone with > display know how will have to look at it. Cc: Ville. BR, Jani. > > Regards, > > Tvrtko > >> @@ -467,8 +470,6 @@ intel_ddi_transcoder_func_reg_val_get(struct intel_encoder *encoder, >> case 36: >> temp |= TRANS_DDI_BPC_12; >> break; >> - default: >> - BUG(); >> } >> >> if (crtc_state->hw.adjusted_mode.flags & DRM_MODE_FLAG_PVSYNC) >> @@ -478,6 +479,9 @@ intel_ddi_transcoder_func_reg_val_get(struct intel_encoder *encoder, >> >> if (cpu_transcoder == TRANSCODER_EDP) { >> switch (pipe) { >> + default: >> + MISSING_CASE(pipe); >> + fallthrough; >> case PIPE_A: >> /* On Haswell, can only use the always-on power well for >> * eDP when not using the panel fitter, and when not >> @@ -494,9 +498,6 @@ intel_ddi_transcoder_func_reg_val_get(struct intel_encoder *encoder, >> case PIPE_C: >> temp |= TRANS_DDI_EDP_INPUT_C_ONOFF; >> break; >> - default: >> - BUG(); >> - break; >> } >> } >> >> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c >> index 0decf3d24237..1a421dda36d7 100644 >> --- a/drivers/gpu/drm/i915/display/intel_display.c >> +++ b/drivers/gpu/drm/i915/display/intel_display.c >> @@ -500,6 +500,9 @@ void vlv_wait_port_ready(struct drm_i915_private *dev_priv, >> i915_reg_t dpll_reg; >> >> switch (dig_port->base.port) { >> + default: >> + MISSING_CASE(dig_port->base.port); >> + fallthrough; >> case PORT_B: >> port_mask = DPLL_PORTB_READY_MASK; >> dpll_reg = DPLL(0); >> @@ -513,8 +516,6 @@ void vlv_wait_port_ready(struct drm_i915_private *dev_priv, >> port_mask = DPLL_PORTD_READY_MASK; >> dpll_reg = DPIO_PHY_STATUS; >> break; >> - default: >> - BUG(); >> } >> >> if (intel_de_wait_for_register(dev_priv, dpll_reg, >> @@ -3157,6 +3158,10 @@ static void i9xx_set_pipeconf(const struct intel_crtc_state *crtc_state) >> PIPECONF_DITHER_TYPE_SP; >> >> switch (crtc_state->pipe_bpp) { >> + default: >> + /* Case prevented by intel_choose_pipe_bpp_dither. */ >> + MISSING_CASE(crtc_state->pipe_bpp); >> + fallthrough; >> case 18: >> pipeconf |= PIPECONF_BPC_6; >> break; >> @@ -3166,9 +3171,6 @@ static void i9xx_set_pipeconf(const struct intel_crtc_state *crtc_state) >> case 30: >> pipeconf |= PIPECONF_BPC_10; >> break; >> - default: >> - /* Case prevented by intel_choose_pipe_bpp_dither. */ >> - BUG(); >> } >> } >> >> @@ -3464,6 +3466,10 @@ static void ilk_set_pipeconf(const struct intel_crtc_state *crtc_state) >> val = 0; >> >> switch (crtc_state->pipe_bpp) { >> + default: >> + /* Case prevented by intel_choose_pipe_bpp_dither. */ >> + MISSING_CASE(crtc_state->pipe_bpp); >> + fallthrough; >> case 18: >> val |= PIPECONF_BPC_6; >> break; >> @@ -3476,9 +3482,6 @@ static void ilk_set_pipeconf(const struct intel_crtc_state *crtc_state) >> case 36: >> val |= PIPECONF_BPC_12; >> break; >> - default: >> - /* Case prevented by intel_choose_pipe_bpp_dither. */ >> - BUG(); >> } >> >> if (crtc_state->dither) >> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h >> index 408152f9f46a..8b10ef5153f2 100644 >> --- a/drivers/gpu/drm/i915/display/intel_display_types.h >> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h >> @@ -1727,13 +1727,14 @@ static inline enum dpio_channel >> vlv_dig_port_to_channel(struct intel_digital_port *dig_port) >> { >> switch (dig_port->base.port) { >> + default: >> + MISSING_CASE(dig_port->base.port); >> + fallthrough; >> case PORT_B: >> case PORT_D: >> return DPIO_CH0; >> case PORT_C: >> return DPIO_CH1; >> - default: >> - BUG(); >> } >> } >> >> @@ -1741,13 +1742,14 @@ static inline enum dpio_phy >> vlv_dig_port_to_phy(struct intel_digital_port *dig_port) >> { >> switch (dig_port->base.port) { >> + default: >> + MISSING_CASE(dig_port->base.port); >> + fallthrough; >> case PORT_B: >> case PORT_C: >> return DPIO_PHY0; >> case PORT_D: >> return DPIO_PHY1; >> - default: >> - BUG(); >> } >> } >> >> @@ -1755,13 +1757,14 @@ static inline enum dpio_channel >> vlv_pipe_to_channel(enum pipe pipe) >> { >> switch (pipe) { >> + default: >> + MISSING_CASE(pipe); >> + fallthrough; >> case PIPE_A: >> case PIPE_C: >> return DPIO_CH0; >> case PIPE_B: >> return DPIO_CH1; >> - default: >> - BUG(); >> } >> } >> -- Jani Nikula, Intel Open Source Graphics Center