Linux-PCI Archive on lore.kernel.org
 help / color / Atom feed
From: Marek Vasut <marek.vasut@gmail.com>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-pci <linux-pci@vger.kernel.org>,
	Marek Vasut <marek.vasut+renesas@gmail.com>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Phil Edworthy <phil.edworthy@renesas.com>,
	Simon Horman <horms+renesas@verge.net.au>,
	Wolfram Sang <wsa@the-dreams.de>,
	Linux-Renesas <linux-renesas-soc@vger.kernel.org>
Subject: Re: [PATCH 2/2] PCI: rcar: Replace unsigned long with u32 in register accessors
Date: Mon, 25 Mar 2019 12:36:35 +0100
Message-ID: <8d107ef9-608e-2077-c32e-3454914e6dee@gmail.com> (raw)
In-Reply-To: <CAMuHMdURsR3ReGejsMnToQu+xoXCdaoRWxFg1r8yAcmWvQAXOw@mail.gmail.com>

On 3/25/19 9:06 AM, Geert Uytterhoeven wrote:
> Hi Marek,
> 
> On Thu, Mar 21, 2019 at 4:20 AM Marek Vasut <marek.vasut@gmail.com> wrote:
>> On 3/18/19 9:19 AM, Geert Uytterhoeven wrote:
>>> On Mon, Mar 18, 2019 at 12:39 AM Marek Vasut <marek.vasut@gmail.com> wrote:
>>>> On 3/17/19 11:22 AM, Geert Uytterhoeven wrote:
>>>>> On Sun, Mar 17, 2019 at 1:06 AM Marek Vasut <marek.vasut@gmail.com> wrote:
>>>>>> On 3/11/19 10:41 AM, Geert Uytterhoeven wrote:
>>>>>>> On Sat, Mar 9, 2019 at 1:56 AM <marek.vasut@gmail.com> wrote:
>>>>>>>> --- a/drivers/pci/controller/pcie-rcar.c
>>>>>>>> +++ b/drivers/pci/controller/pcie-rcar.c
>>>>>>>> @@ -152,14 +152,12 @@ struct rcar_pcie {
>>>>>>>>         struct                  rcar_msi msi;
>>>>>>>>  };
>>>>>>>>
>>>>>>>> -static void rcar_pci_write_reg(struct rcar_pcie *pcie, unsigned long val,
>>>>>>>> -                              unsigned long reg)
>>>>>>>> +static void rcar_pci_write_reg(struct rcar_pcie *pcie, u32 val, u32 reg)
>>>>>>>
>>>>>>> Doesn't unsigned int make more sense for reg?
>>>>>>
>>>>>> Isn't u32 more explicit ?
>>>>>
>>>>> It's just an offset in the register block, with a range much smaller than u32.
>>>>
>>>> We could use u16 ?
>>>
>>> u16 may be more expensive on some processor architectures
>>> (MIPS comes too mind, don't know about ARM).
>>
>> On armv8a, none.
>>
>>>> However, Bjorn's concern was that using unsigned long
>>>> for registers was not recommended ;
>>>
>>> Wasn't that comment meant for the size of the register values?
>>>
>>>> how's unsigned int better ?
>>>
>>> Basic rule "If you don't care about the size, use (unsigned) int"?
>>
>> This only applies to the $shift variable, yes ? The rest are u32 since
>> those contain actual values read/written into the registers.
> 
> There is no "shift" variable. "reg" is a register offset, not an actual register
> value.

Sure

-- 
Best regards,
Marek Vasut

  reply index

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-09  0:56 [PATCH 1/2] PCI: rcar: Clean up remaining macros defining bits marek.vasut
2019-03-09  0:56 ` [PATCH 2/2] PCI: rcar: Replace unsigned long with u32 in register accessors marek.vasut
2019-03-09 11:14   ` Niklas Söderlund
2019-03-11  9:41   ` Geert Uytterhoeven
2019-03-16 23:59     ` Marek Vasut
2019-03-17 10:22       ` Geert Uytterhoeven
2019-03-17 22:50         ` Marek Vasut
2019-03-18  8:19           ` Geert Uytterhoeven
2019-03-21  3:20             ` Marek Vasut
2019-03-25  8:06               ` Geert Uytterhoeven
2019-03-25 11:36                 ` Marek Vasut [this message]
2019-03-09 11:10 ` [PATCH 1/2] PCI: rcar: Clean up remaining macros defining bits Niklas Söderlund
2019-03-11  9:32 ` Geert Uytterhoeven

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=8d107ef9-608e-2077-c32e-3454914e6dee@gmail.com \
    --to=marek.vasut@gmail.com \
    --cc=geert+renesas@glider.be \
    --cc=geert@linux-m68k.org \
    --cc=horms+renesas@verge.net.au \
    --cc=linux-pci@vger.kernel.org \
    --cc=linux-renesas-soc@vger.kernel.org \
    --cc=marek.vasut+renesas@gmail.com \
    --cc=phil.edworthy@renesas.com \
    --cc=wsa@the-dreams.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-PCI Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-pci/0 linux-pci/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-pci linux-pci/ https://lore.kernel.org/linux-pci \
		linux-pci@vger.kernel.org
	public-inbox-index linux-pci

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-pci


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git