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[149.200.78.10]) by smtp.gmail.com with ESMTPSA id a101sm12083131edf.76.2020.08.01.05.24.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 01 Aug 2020 05:24:35 -0700 (PDT) From: "Saheed O. Bolarinwa" To: helgaas@kernel.org, David Airlie , Daniel Vetter Cc: "Saheed O. Bolarinwa" , bjorn@helgaas.com, skhan@linuxfoundation.org, linux-kernel-mentees@lists.linuxfoundation.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Subject: [RFC PATCH 09/17] drm/i915/vga: Drop uses of pci_read_config_*() return value Date: Sat, 1 Aug 2020 13:24:38 +0200 Message-Id: <20200801112446.149549-10-refactormyself@gmail.com> X-Mailer: git-send-email 2.18.4 In-Reply-To: <20200801112446.149549-1-refactormyself@gmail.com> References: <20200801112446.149549-1-refactormyself@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The return value of pci_read_config_*() may not indicate a device error. However, the value read by these functions is more likely to indicate this kind of error. This presents two overlapping ways of reporting errors and complicates error checking. It is possible to move to one single way of checking for error if the dependency on the return value of these functions is removed, then it can later be made to return void. Remove all uses of the return value of pci_read_config_*(). Check the actual value read for ~0. In this case, ~0 is an invalid value thus it indicates some kind of error. Suggested-by: Bjorn Helgaas Signed-off-by: Saheed O. Bolarinwa --- drivers/gpu/drm/i915/display/intel_vga.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_vga.c b/drivers/gpu/drm/i915/display/intel_vga.c index be333699c515..6f9406699c9d 100644 --- a/drivers/gpu/drm/i915/display/intel_vga.c +++ b/drivers/gpu/drm/i915/display/intel_vga.c @@ -99,7 +99,8 @@ intel_vga_set_state(struct drm_i915_private *i915, bool enable_decode) unsigned int reg = INTEL_GEN(i915) >= 6 ? SNB_GMCH_CTRL : INTEL_GMCH_CTRL; u16 gmch_ctrl; - if (pci_read_config_word(i915->bridge_dev, reg, &gmch_ctrl)) { + pci_read_config_word(i915->bridge_dev, reg, &gmch_ctrl); + if (gmch_ctrl == (u16)~0) { drm_err(&i915->drm, "failed to read control word\n"); return -EIO; } -- 2.18.4