mail archive of the barebox mailing list
 help / color / mirror / Atom feed
From: Sascha Hauer <s.hauer@pengutronix.de>
To: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: barebox@lists.infradead.org
Subject: Re: [PATCH 03/18] [RFC] at91: Make IS_ERR work for I/O pointers
Date: Wed, 17 Feb 2016 09:34:24 +0100	[thread overview]
Message-ID: <20160217083424.GQ19372@pengutronix.de> (raw)
In-Reply-To: <1455672559-25061-4-git-send-email-andrew.smirnov@gmail.com>

On Tue, Feb 16, 2016 at 05:29:04PM -0800, Andrey Smirnov wrote:
> Having this functionality partially "broken" opens the door for subtle
> bugs in peripheral drivers for AT91 platform since it not straight out
> obvious that IS_ERR might return a false positive.
> 
> It also makes it much harder to judge the correctness of the driver
> code, for example it is perfectly fine to use IS_ERR in at91-i2c.c since
> I2C controller's register file is located at 0xFFFA_C000 (which it
> doesn't but that's the subject for another patch), however one couldn't
> help but wonder how the code it sam9_smc.c could possibly work given how
> that module is located at 0xFFFF_EC00.

0x100000000 - MAX_ERRNO is still bigger than 0xFFFFEC00, so this should
work.

The workaround you suggest is sooo ugly, do we really need this? How
many places are really affected by false positives in IS_ERR_VALUE?

Another solution, although a job for someone familiar with coccinelle
would be to change the prototype of dev_request_mem_region to

int dev_request_mem_region(struct device_d *dev, int num, void __iomem **base);

Sascha

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

_______________________________________________
barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

  reply	other threads:[~2016-02-17  8:34 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-17  1:29 [PATCH 00/17] RFC for additional 'nvmem' plumbing Andrey Smirnov
2016-02-17  1:29 ` [PATCH 01/18] common: Add EPROBE_DEFER to strerror Andrey Smirnov
2016-02-17  1:29 ` [PATCH 02/18] base: driver.c: Coalesce error checking code Andrey Smirnov
2016-02-17  1:29 ` [PATCH 03/18] [RFC] at91: Make IS_ERR work for I/O pointers Andrey Smirnov
2016-02-17  8:34   ` Sascha Hauer [this message]
2016-02-17 20:39     ` Andrey Smirnov
2016-02-18 10:26       ` Sascha Hauer
2016-02-17  1:29 ` [PATCH 04/18] [RFC] base/driver.c: Remove dev_request_mem_region_err_null Andrey Smirnov
2016-02-17  1:29 ` [PATCH 05/18] i2c-at91: Use IS_ERR instead of checking for NULL Andrey Smirnov
2016-02-17  1:29 ` [PATCH 06/18] clk-imx6: Call clk_enable on mmdc_ch0_axi_podf Andrey Smirnov
2016-02-17  1:29 ` [PATCH 07/18] fec_imx: Deallocate clocks when probe fails Andrey Smirnov
2016-02-17  1:29 ` [PATCH 08/18] [RFC] base: Introduce dev_request_mem_resource Andrey Smirnov
2016-02-17  1:29 ` [PATCH 09/18] fec_imx: Deallocate I/O resources if probe fails Andrey Smirnov
2016-02-17  1:29 ` [PATCH 10/18] fec_imx: Free phy_reset GPIO if when " Andrey Smirnov
2016-02-17  1:29 ` [PATCH 11/18] fec_imx: Use FEC_ECNTRL_RESET instead of a magic number Andrey Smirnov
2016-02-17  1:29 ` [PATCH 12/18] fec_imx: Impelemnt reset timeout Andrey Smirnov
2016-02-17  8:43   ` Sascha Hauer
2016-02-17  1:29 ` [PATCH 13/18] fec_imx: Deallocate DMA buffers when probe fails Andrey Smirnov
2016-02-17  1:29 ` [PATCH 14/18] fec_imx: Unregister MDIO " Andrey Smirnov
2016-02-17  1:29 ` [PATCH 15/18] [RFC] net: eth: Always use DEVICE_ID_DYNAMIC Andrey Smirnov
2016-02-17  2:40   ` Trent Piepho
2016-02-17  4:16     ` Andrey Smirnov
2016-02-18 19:30       ` Trent Piepho
2016-02-19 17:17         ` Andrey Smirnov
2016-02-17  1:29 ` [PATCH 16/18] [RFC] nvmem: Add of_nvmem_cell_from_cell_np Andrey Smirnov
2016-02-17  1:29 ` [PATCH 17/18] [RFC] nvmem: Add nvmem-ro-of-blob driver Andrey Smirnov
2016-02-17  8:52   ` Sascha Hauer
2016-02-17 20:40     ` Andrey Smirnov
2016-02-17  1:29 ` [PATCH 18/18] [RFC] nvmem: Add nvmem-sg driver Andrey Smirnov
2016-02-17  3:09 ` [PATCH 00/17] RFC for additional 'nvmem' plumbing Trent Piepho
2016-02-17  4:20   ` Andrey Smirnov

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=20160217083424.GQ19372@pengutronix.de \
    --to=s.hauer@pengutronix.de \
    --cc=andrew.smirnov@gmail.com \
    --cc=barebox@lists.infradead.org \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox