From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 832F1235041; Thu, 7 Aug 2025 07:37:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754552231; cv=none; b=a0Sbk9XY0+PG1AmS1iWJGYsAh7JWvqK5zgx7OaQAwHhvtdpoIk93lVsDGa4CGIB6QP2Xo0dxa0XWxox38CUGplihL7J99y+DyGWs3BNXWAJ2qRCfId2ap7+fYvxHIlayLpUxVJWO/cuPL7dZQ7kkUNcJ6AMrKjTJGBPQmnkvmGg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754552231; c=relaxed/simple; bh=lFMthv6QrKBOTRITI6/tRl8fokRfUTY5lwM7iuvzmlM=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=mlHuMS0RSCU+LgWysD7FFFDJPdOrPp+IjysjPB20Qc+i8VlD5aH7fr81SKlTUwvH5d7hDzvlK9knC0zM2Y27RYpCokX6Yj4mPTBoSqi+ZdNc9mPll27Kz7WLSUszydeMFRLPw1tYjHtbpw6MsvIN58s2X53a7Skb+A8u94TZT3A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=f3igw4UG; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="f3igw4UG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66FAAC4CEEB; Thu, 7 Aug 2025 07:37:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754552231; bh=lFMthv6QrKBOTRITI6/tRl8fokRfUTY5lwM7iuvzmlM=; h=Date:Subject:From:To:Cc:References:In-Reply-To:From; b=f3igw4UGfk9jmIHErNNNdAstrdBymQJsFP03lam5JbZcRKPRT9yQvrIzkf6i5gIA0 /jvrOdwAigpIpIsn49AJBeKHHaIjKbcsPHs/oeiFWFUSlbwk+1ewkVJvGl5FBS7QJp yatohQrhjetYzipktlwyQbdukkjT4N8JSPFD0bx6g/IopgqMBZTIh+y6Wb4B0dJYvG yh+CtW+8salgTqNltB+FlQkPkzeClthV4yCQfTatLx3h3DJ/O2HW5UEGB8rVbbAIKI /e45UWT19lDn2djtCp7IwtR35gPYcqKtsE+nBM6veEm1ZTk+71iwrrjOuMI7UxnfIV hhYS5Dk3SZz8w== Message-ID: <8fa64c82-d5f8-4045-8ebf-5b938df8cc7c@kernel.org> Date: Thu, 7 Aug 2025 09:37:07 +0200 Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 1/2] tty: serial/8250: Fix build warning in serial8250_probe_acpi() From: Jiri Slaby To: Arnd Bergmann , Abinash Singh , Greg Kroah-Hartman Cc: Andy Shevchenko , Sunil V L , =?UTF-8?Q?Uwe_Kleine-K=C3=B6nig?= , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org References: <20250805195155.742004-1-abinashsinghlalotra@gmail.com> <22204a4a-9c10-4aca-8159-a0e69c74cb34@kernel.org> Content-Language: en-US Autocrypt: addr=jirislaby@kernel.org; keydata= xsFNBE6S54YBEACzzjLwDUbU5elY4GTg/NdotjA0jyyJtYI86wdKraekbNE0bC4zV+ryvH4j rrcDwGs6tFVrAHvdHeIdI07s1iIx5R/ndcHwt4fvI8CL5PzPmn5J+h0WERR5rFprRh6axhOk rSD5CwQl19fm4AJCS6A9GJtOoiLpWn2/IbogPc71jQVrupZYYx51rAaHZ0D2KYK/uhfc6neJ i0WqPlbtIlIrpvWxckucNu6ZwXjFY0f3qIRg3Vqh5QxPkojGsq9tXVFVLEkSVz6FoqCHrUTx wr+aw6qqQVgvT/McQtsI0S66uIkQjzPUrgAEtWUv76rM4ekqL9stHyvTGw0Fjsualwb0Gwdx ReTZzMgheAyoy/umIOKrSEpWouVoBt5FFSZUyjuDdlPPYyPav+hpI6ggmCTld3u2hyiHji2H cDpcLM2LMhlHBipu80s9anNeZhCANDhbC5E+NZmuwgzHBcan8WC7xsPXPaiZSIm7TKaVoOcL 9tE5aN3jQmIlrT7ZUX52Ff/hSdx/JKDP3YMNtt4B0cH6ejIjtqTd+Ge8sSttsnNM0CQUkXps w98jwz+Lxw/bKMr3NSnnFpUZaxwji3BC9vYyxKMAwNelBCHEgS/OAa3EJoTfuYOK6wT6nadm YqYjwYbZE5V/SwzMbpWu7Jwlvuwyfo5mh7w5iMfnZE+vHFwp/wARAQABzSFKaXJpIFNsYWJ5 IDxqaXJpc2xhYnlAa2VybmVsLm9yZz7CwXcEEwEIACEFAlW3RUwCGwMFCwkIBwIGFQgJCgsC BBYCAwECHgECF4AACgkQvSWxBAa0cEnVTg//TQpdIAr8Tn0VAeUjdVIH9XCFw+cPSU+zMSCH eCZoA/N6gitEcnvHoFVVM7b3hK2HgoFUNbmYC0RdcSc80pOF5gCnACSP9XWHGWzeKCARRcQR 4s5YD8I4VV5hqXcKo2DFAtIOVbHDW+0okOzcecdasCakUTr7s2fXz97uuoc2gIBB7bmHUGAH XQXHvdnCLjDjR+eJN+zrtbqZKYSfj89s/ZHn5Slug6w8qOPT1sVNGG+eWPlc5s7XYhT9z66E l5C0rG35JE4PhC+tl7BaE5IwjJlBMHf/cMJxNHAYoQ1hWQCKOfMDQ6bsEr++kGUCbHkrEFwD UVA72iLnnnlZCMevwE4hc0zVhseWhPc/KMYObU1sDGqaCesRLkE3tiE7X2cikmj/qH0CoMWe gjnwnQ2qVJcaPSzJ4QITvchEQ+tbuVAyvn9H+9MkdT7b7b2OaqYsUP8rn/2k1Td5zknUz7iF oJ0Z9wPTl6tDfF8phaMIPISYrhceVOIoL+rWfaikhBulZTIT5ihieY9nQOw6vhOfWkYvv0Dl o4GRnb2ybPQpfEs7WtetOsUgiUbfljTgILFw3CsPW8JESOGQc0Pv8ieznIighqPPFz9g+zSu Ss/rpcsqag5n9rQp/H3WW5zKUpeYcKGaPDp/vSUovMcjp8USIhzBBrmI7UWAtuedG9prjqfO wU0ETpLnhgEQAM+cDWLL+Wvc9cLhA2OXZ/gMmu7NbYKjfth1UyOuBd5emIO+d4RfFM02XFTI t4MxwhAryhsKQQcA4iQNldkbyeviYrPKWjLTjRXT5cD2lpWzr+Jx7mX7InV5JOz1Qq+P+nJW YIBjUKhI03ux89p58CYil24Zpyn2F5cX7U+inY8lJIBwLPBnc9Z0An/DVnUOD+0wIcYVnZAK DiIXODkGqTg3fhZwbbi+KAhtHPFM2fGw2VTUf62IHzV+eBSnamzPOBc1XsJYKRo3FHNeLuS8 f4wUe7bWb9O66PPFK/RkeqNX6akkFBf9VfrZ1rTEKAyJ2uqf1EI1olYnENk4+00IBa+BavGQ 8UW9dGW3nbPrfuOV5UUvbnsSQwj67pSdrBQqilr5N/5H9z7VCDQ0dhuJNtvDSlTf2iUFBqgk 3smln31PUYiVPrMP0V4ja0i9qtO/TB01rTfTyXTRtqz53qO5dGsYiliJO5aUmh8swVpotgK4 /57h3zGsaXO9PGgnnAdqeKVITaFTLY1ISg+Ptb4KoliiOjrBMmQUSJVtkUXMrCMCeuPDGHo7 39Xc75lcHlGuM3yEB//htKjyprbLeLf1y4xPyTeeF5zg/0ztRZNKZicgEmxyUNBHHnBKHQxz 1j+mzH0HjZZtXjGu2KLJ18G07q0fpz2ZPk2D53Ww39VNI/J9ABEBAAHCwV8EGAECAAkFAk6S 54YCGwwACgkQvSWxBAa0cEk3tRAAgO+DFpbyIa4RlnfpcW17AfnpZi9VR5+zr496n2jH/1ld wRO/S+QNSA8qdABqMb9WI4BNaoANgcg0AS429Mq0taaWKkAjkkGAT7mD1Q5PiLr06Y/+Kzdr 90eUVneqM2TUQQbK+Kh7JwmGVrRGNqQrDk+gRNvKnGwFNeTkTKtJ0P8jYd7P1gZb9Fwj9YLx jhn/sVIhNmEBLBoI7PL+9fbILqJPHgAwW35rpnq4f/EYTykbk1sa13Tav6btJ+4QOgbcezWI wZ5w/JVfEJW9JXp3BFAVzRQ5nVrrLDAJZ8Y5ioWcm99JtSIIxXxt9FJaGc1Bgsi5K/+dyTKL wLMJgiBzbVx8G+fCJJ9YtlNOPWhbKPlrQ8+AY52Aagi9WNhe6XfJdh5g6ptiOILm330mkR4g W6nEgZVyIyTq3ekOuruftWL99qpP5zi+eNrMmLRQx9iecDNgFr342R9bTDlb1TLuRb+/tJ98 f/bIWIr0cqQmqQ33FgRhrG1+Xml6UXyJ2jExmlO8JljuOGeXYh6ZkIEyzqzffzBLXZCujlYQ DFXpyMNVJ2ZwPmX2mWEoYuaBU0JN7wM+/zWgOf2zRwhEuD3A2cO2PxoiIfyUEfB9SSmffaK/ S4xXoB6wvGENZ85Hg37C7WDNdaAt6Xh2uQIly5grkgvWppkNy4ZHxE+jeNsU7tg= In-Reply-To: <22204a4a-9c10-4aca-8159-a0e69c74cb34@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 07. 08. 25, 8:43, Jiri Slaby wrote: > On 07. 08. 25, 7:25, Jiri Slaby wrote: >> On 06. 08. 25, 9:01, Arnd Bergmann wrote: >>> Note how serial8250_register_8250_port() ands up just copying >>> individual members of the passed uart_8250_port structure into >>> the global array of the same type, so one way of addressing >>> this would be to use a structure for initialization that only >>> contains a subset of the uart_8250_port members and can still >>> be allocated on the stack, or possibly be constant. >> >> Yes: >> https://lore.kernel.org/all/ >> f84c2ee3-77b4-41c4-8517-26dfb44a2276@kernel.org/ > > As a PoC, these members from uart_8250_port are really used in > serial8250_register_8250_port(): > struct uart_8250_port2 { >         long unsigned int          iobase;               /*     0     8 */ >         resource_size_t            mapbase;              /*     8     8 */ >         unsigned char *            membase;              /*    16     8 */ >         long unsigned int          irqflags;             /*    24     8 */ >         upf_t                      flags;                /*    32     8 */ >         enum uart_iotype           iotype;               /*    40     4 */ >         unsigned int               tx_loadsz;            /*    44     4 */ >         unsigned int               type;                 /*    48     4 */ >         u32                        overrun_backoff_time_ms; /*    52  4 */ >         u32                        capabilities;         /*    56     4 */ >         unsigned int               line;                 /*    60     4 */ >         /* --- cacheline 1 boundary (64 bytes) --- */ >         unsigned int               uartclk;              /*    64     4 */ >         unsigned int               ctrl_id;              /*    68     4 */ >         unsigned int               port_id;              /*    72     4 */ >         unsigned int               irq;                  /*    76     4 */ >         unsigned int               fifosize;             /*    80     4 */ >         u16                        bugs;                 /*    84     2 */ >         u16                        lsr_save_mask;        /*    86     2 */ >         unsigned char              regshift;             /*    88     1 */ >         unsigned char              hub6;                 /*    89     1 */ > >         /* XXX 6 bytes hole, try to pack */ > >         resource_size_t            mapsize;              /*    96     8 */ >         struct serial_rs485        rs485;                /*   104    32 */ >         /* --- cacheline 2 boundary (128 bytes) was 8 bytes ago --- */ >         struct serial_rs485        rs485_supported;      /*   136    32 */ >         void *                     private_data;         /*   168     8 */ >         struct uart_8250_dma *     dma;                  /*   176     8 */ And if in the above link mentioned conversion to ops [1] is finished, we would replace all the below by a single pointer to a const ops. The struct would be then 176+8. [1] the two "ops" commits at https://git.kernel.org/pub/scm/linux/kernel/git/jirislaby/linux.git/log/?h=devel >         void                       (*rs485_start_tx)(struct > uart_8250_port *, bool); /*   184     8 */ >         /* --- cacheline 3 boundary (192 bytes) --- */ >         void                       (*rs485_stop_tx)(struct > uart_8250_port *, bool); /*   192     8 */ >         void                       (*throttle)(struct uart_port *); /* >  200     8 */ >         void                       (*unthrottle)(struct uart_port *); / > *   208     8 */ >         u32                        (*serial_in)(struct uart_port *, > unsigned int); /*   216     8 */ >         void                       (*serial_out)(struct uart_port *, > unsigned int, u32); /*   224     8 */ >         void                       (*set_termios)(struct uart_port *, > struct ktermios *, const struct ktermios  *); /*   232     8 */ >         void                       (*set_ldisc)(struct uart_port *, > struct ktermios *); /*   240     8 */ >         unsigned int               (*get_mctrl)(struct uart_port *); /* >   248     8 */ >         /* --- cacheline 4 boundary (256 bytes) --- */ >         void                       (*set_mctrl)(struct uart_port *, > unsigned int); /*   256     8 */ >         unsigned int               (*get_divisor)(struct uart_port *, > unsigned int, unsigned int *); /*   264     8 */ >         void                       (*set_divisor)(struct uart_port *, > unsigned int, unsigned int, unsigned int); /*   272     8 */ >         int                        (*startup)(struct uart_port *); /* > 280     8 */ >         void                       (*shutdown)(struct uart_port *); /* >  288     8 */ >         int                        (*handle_irq)(struct uart_port *); / > *   296     8 */ >         void                       (*pm)(struct uart_port *, unsigned > int, unsigned int); /*   304     8 */ >         void                       (*handle_break)(struct uart_port > *); /*   312     8 */ >         /* --- cacheline 5 boundary (320 bytes) --- */ >         int                        (*rs485_config)(struct uart_port *, > struct ktermios *, struct serial_rs485 *); /*   320     8 */ >         struct device *            dev;                  /*   328     8 */ >         u32                        (*dl_read)(struct uart_8250_port > *); /*   336     8 */ >         void                       (*dl_write)(struct uart_8250_port *, > u32); /*   344     8 */ > >         /* size: 352, cachelines: 6, members: 46 */ >         /* sum members: 346, holes: 1, sum holes: 6 */ >         /* last cacheline: 32 bytes */ > }; > > -- js suse labs