Re: [PATCH 8/8] acpi: Use booleans when probing different _DSM types

From: Samuel Pitoiset <samuel.pitoiset-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
To: Pierre Moreau <pierre.morrow-GANU6spQydw@public.gmane.org>,
	nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org
Cc: bskeggs-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org,
	dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org
Subject: Re: [PATCH 8/8] acpi: Use booleans when probing different _DSM types
Date: Tue, 26 May 2015 22:42:10 +0200	[thread overview]
Message-ID: <5564DAA2.2070800@gmail.com> (raw)
In-Reply-To: <1279603096.13154002.1432644369153.JavaMail.root-x5ewXQG5twBsFmKuirFwRhh1pbbyJDp15NbjCUgZEJk@public.gmane.org>

On 05/26/2015 02:46 PM, Pierre Moreau wrote:
> I'm thinking of re-writing this patch to just OR the different returned retval and test for individual bits directly in the final conditionals.
> So this would give something like:
>
>
> int retval = 0;
>
> while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
> 	vga_count++;
> 	retval |= nouveau_dsm_pci_probe(pdev);
> }
> while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_3D << 8, pdev)) != NULL) {
> 	vga_count++;
> 	retval |= nouveau_dsm_pci_probe(pdev);
> }
>
> if (retval & NOUVEAU_DSM_HAS_OPT) {
> 	acpi_get_name(nouveau_dsm_priv.dhandle, ACPI_FULL_PATHNAME,
> 		&buffer);
> 	printk(KERN_INFO "VGA switcheroo: detected Optimus DSM method %s handle\n",
> 		acpi_method_name);
> 	nouveau_dsm_priv.optimus_detected = true;
> 	ret = true;
> } else if (vga_count == 2 && (retval & NOUVEAU_DSM_HAS_MUX) && guid_valid) {
> 	acpi_get_name(nouveau_dsm_priv.dhandle, ACPI_FULL_PATHNAME,
> 		&buffer);
> 	printk(KERN_INFO "VGA switcheroo: detected mux DSM switching method %s handle\n",
> 		acpi_method_name);
> 	nouveau_dsm_priv.mux_detected = true;
> 	ret = true;
> } else if (retval & NOUVEAU_DSM_HAS_GMUX) {
> 	acpi_get_name(nouveau_dsm_priv.dhandle, ACPI_FULL_PATHNAME,
> 		&buffer);
> 	printk(KERN_INFO "VGA switcheroo: detected gmux DSM switching method %s handle\n",
> 		acpi_method_name);
> 	nouveau_dsm_priv.gmux_detected = true;
> 	ret = true;
> }
>
>
> Any opinions on this?

If this improves readability of the code, go ahead.

>
> Pierre
>
> ----- Mail original -----
>> Signed-off-by: Pierre Moreau <pierre.morrow@free.fr>
>> ---
>>   drm/nouveau/nouveau_acpi.c | 14 +++++++-------
>>   1 file changed, 7 insertions(+), 7 deletions(-)
>>
>> diff --git a/drm/nouveau/nouveau_acpi.c b/drm/nouveau/nouveau_acpi.c
>> index 3d6a1ea..5d63621 100644
>> --- a/drm/nouveau/nouveau_acpi.c
>> +++ b/drm/nouveau/nouveau_acpi.c
>> @@ -297,8 +297,8 @@ static bool nouveau_dsm_detect(void)
>>   	char acpi_method_name[255] = { 0 };
>>   	struct acpi_buffer buffer = {sizeof(acpi_method_name),
>>   	acpi_method_name};
>>   	struct pci_dev *pdev = NULL;
>> -	int has_dsm = 0;
>> -	int has_optimus = 0;
>> +	bool has_mux = false;
>> +	bool has_optimus = false;
>>   	bool has_gmux = false;
>>   	int vga_count = 0;
>>   	bool guid_valid;
>> @@ -317,9 +317,9 @@ static bool nouveau_dsm_detect(void)
>>   
>>   		retval = nouveau_dsm_pci_probe(pdev);
>>   		if (retval & NOUVEAU_DSM_HAS_MUX)
>> -			has_dsm |= 1;
>> +			has_mux = true;
>>   		if (retval & NOUVEAU_DSM_HAS_OPT)
>> -			has_optimus = 1;
>> +			has_optimus = true;
>>   		if (retval & NOUVEAU_DSM_HAS_GMUX)
>>   			has_gmux = true;
>>   	}
>> @@ -329,9 +329,9 @@ static bool nouveau_dsm_detect(void)
>>   
>>   		retval = nouveau_dsm_pci_probe(pdev);
>>   		if (retval & NOUVEAU_DSM_HAS_MUX)
>> -			has_dsm |= 1;
>> +			has_mux = true;
>>   		if (retval & NOUVEAU_DSM_HAS_OPT)
>> -			has_optimus = 1;
>> +			has_optimus = true;
>>   		if (retval & NOUVEAU_DSM_HAS_GMUX)
>>   			has_gmux = true;
>>   	}
>> @@ -344,7 +344,7 @@ static bool nouveau_dsm_detect(void)
>>   			acpi_method_name);
>>   		nouveau_dsm_priv.optimus_detected = true;
>>   		ret = true;
>> -	} else if (vga_count == 2 && has_dsm && guid_valid) {
>> +	} else if (vga_count == 2 && has_mux && guid_valid) {
>>   		acpi_get_name(nouveau_dsm_priv.dhandle, ACPI_FULL_PATHNAME,
>>   			&buffer);
>>   		printk(KERN_INFO "VGA switcheroo: detected mux DSM switching
>>   		method %s handle\n",
>> --
>> 2.4.1
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
>>
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