From: Alexey Charkov <alchark@gmail.com>
To: Paul Mundt <lethal@linux-sh.org>
Cc: linux-arm-kernel@lists.infradead.org,
vt8500-wm8505-linux-kernel@googlegroups.com,
Andrew Morton <akpm@linux-foundation.org>,
Guennadi Liakhovetski <g.liakhovetski@gmx.de>,
Florian Tobias Schandinat <FlorianSchandinat@gmx.de>,
Ralf Baechle <ralf@linux-mips.org>,
"David S. Miller" <davem@davemloft.net>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 6/6 v2] ARM: Add support for the display controllers in VT8500 and WM8505
Date: Mon, 8 Nov 2010 12:56:42 +0000 [thread overview]
Message-ID: <AANLkTimkrK9T7G3=K_Ob1SuK64DrGJD3WNoangPp_ryW@mail.gmail.com> (raw)
In-Reply-To: <20101108041721.GA11605@linux-sh.org>
2010/11/8 Paul Mundt <lethal@linux-sh.org>:
> On Sun, Nov 07, 2010 at 07:28:57PM +0300, Alexey Charkov wrote:
>> +static int __devinit vt8500lcd_probe(struct platform_device *pdev)
>> +{
>
> ...
>
>> + addr = fbi;
>> + addr = addr + sizeof(struct vt8500lcd_info);
>> + fbi->fb.pseudo_palette = addr;
>> +
> ...
>
>> + fbi->palette_size = PAGE_ALIGN(512);
>> + fbi->palette_cpu = dma_alloc_coherent(&pdev->dev,
>> + fbi->palette_size,
>> + &fbi->palette_phys,
>> + GFP_KERNEL);
>> + if (fbi->fb.pseudo_palette == NULL) {
>> + dev_err(&pdev->dev, "Failed to allocate palette buffer\n");
>> + ret = -ENOMEM;
>> + goto failed_free_io;
>> + }
>> +
> This looks like a bogus test, you've already allocated enough space for
> the pseudo_palette and will have bailed out on the kmalloc() failing well
> before this. You also don't have any error handling for fbi->palette_cpu,
> which is presumably what you intended to do here.
>
True, this has to be corrected (old copy-paste error left unnoticed
somehow). It's also deallocated wrongly in the error path, which I
have just noticed.
>> +static int __devexit vt8500lcd_remove(struct platform_device *pdev)
>> +{
>> + struct vt8500lcd_info *fbi = platform_get_drvdata(pdev);
>> + struct resource *res;
>> + int irq;
>> +
>> + if (!fbi)
>> + return 0;
>> +
>> + unregister_framebuffer(&fbi->fb);
>> +
>> + writel(0, fbi->regbase);
>> +
>> + if (fbi->fb.cmap.len)
>> + fb_dealloc_cmap(&fbi->fb.cmap);
>> +
>> + irq = platform_get_irq(pdev, 0);
>> + free_irq(irq, fbi);
>> +
>> + iounmap(fbi->regbase);
>> +
>
> You're also missing a dma_free_coherent() here.
>
True, will be fixed.
>> +static int __devinit wm8505fb_probe(struct platform_device *pdev)
>> +{
>> + fbi->fb.screen_base = pdata->video_mem_virt;
>> + fbi->fb.screen_size = pdata->video_mem_len;
>> +
> ...
>
>> +failed_free_mem:
>> + free_pages_exact(fbi->fb.screen_base, fbi->fb.screen_size);
>
> ...
>
> What in the name of all that is holy are you doing here? If you need to
> have your platform deal with virtual address allocation and freeing then
> you should pass in callbacks for that and hide the instrumentation
> details there. Presently this is tying you down to an alloc_pages_exact()
> interface buried in the board setup, which isn't going to mesh well with
> other platforms that may wish to go about this an alternate way (like
> memblock reservations).
>
Actually, this is a leftover from a previous implementation with
alloc_pages_exact(), which could not work for larger screen sizes (due
to the framebuffer growing over 4MB). Now memory is reserved via
memblock, so this should have probably been just dropped.
>> diff --git a/drivers/video/wmt_ge_rops.c b/drivers/video/wmt_ge_rops.c
>> new file mode 100644
>> index 0000000..c71f97e
>> --- /dev/null
>> +++ b/drivers/video/wmt_ge_rops.c
>> +void __iomem *regbase;
>> +
> Uhm, no. If this is only used in this driver then just make it static.
> Given that you are using the driver model here though and could
> theoretically support multiple rop engines, you're much better off making
> this private data and burying it under the appropriate per-device data
> structures.
>
Is that platform_{set,get}_drvdata() what you are talking about? Using
multiple engines seems extremely unlikely, though :)
>> +int wmt_ge_sync(struct fb_info *p)
>> +{
>> + while (readl(regbase + GE_STATUS_OFF) & 4)
>> + /* busy wait */;
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL(wmt_ge_sync);
>> +
> While I admire your optimism in your hardware, experience suggests you
> really want a timeout here. You may also wish to insert a cpu_relax()
> here.
>
I wonder if this callback is allowed to sleep? In principle, the
hardware seems to support interrupt generation on operation
completion, so maybe wait_event_interruptible_timeout() could be used
here to remove the busy wait altogether?
Thank you for the comments, Paul!
Best regards,
Alexey
next prev parent reply other threads:[~2010-11-08 12:56 UTC|newest]
Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-07 16:28 [PATCH 1/6 v2] ARM: Add basic architecture support for VIA/WonderMedia 85xx SoC's Alexey Charkov
2010-11-07 16:28 ` [PATCH 2/6 v2] serial: Add support for UART on VIA VT8500 and compatibles Alexey Charkov
2010-11-07 23:08 ` Alan Cox
2010-11-08 0:58 ` [PATCH 2/6 v3] " Alexey Charkov
2010-11-08 10:46 ` Alan Cox
2010-11-08 17:33 ` [PATCH 2/6 v4] " Alexey Charkov
2010-11-07 16:28 ` [PATCH 3/6 v2] input: Add support for VIA VT8500 and compatibles in i8042 Alexey Charkov
2010-11-12 22:54 ` Alexey Charkov
2010-11-12 23:30 ` Dmitry Torokhov
2010-11-13 0:00 ` Alexey Charkov
2010-12-22 21:41 ` [PATCH 3/6 v3] " Alexey Charkov
2010-11-07 16:28 ` [PATCH 4/6 v2] usb: Add support for VIA VT8500 and compatibles in EHCI HCD Alexey Charkov
2010-11-07 16:28 ` [PATCH 5/6 v2] rtc: Add support for the RTC in VIA VT8500 and compatibles Alexey Charkov
2010-11-12 22:53 ` Alexey Charkov
2010-11-13 12:14 ` Lars-Peter Clausen
2010-11-13 23:56 ` [PATCH 5/6 v3] " Alexey Charkov
2010-11-14 15:50 ` Lars-Peter Clausen
2010-11-14 17:00 ` [PATCH 5/6 v4] " Alexey Charkov
2010-11-23 19:17 ` Alexey Charkov
2010-11-24 19:23 ` Lars-Peter Clausen
2010-11-24 22:47 ` [PATCH 5/6 v5] " Alexey Charkov
2010-11-07 16:28 ` [PATCH 6/6 v2] ARM: Add support for the display controllers in VT8500 and WM8505 Alexey Charkov
2010-11-08 4:17 ` Paul Mundt
2010-11-08 12:56 ` Alexey Charkov [this message]
2010-11-08 14:14 ` [PATCH 6/6 v3] " Alexey Charkov
2010-11-08 20:43 ` Paul Mundt
2010-11-08 21:15 ` Alexey Charkov
2010-11-08 21:30 ` Paul Mundt
2010-11-08 23:42 ` [PATCH 6/6 v4] " Alexey Charkov
2010-11-08 23:54 ` Paul Mundt
2010-11-09 0:03 ` Alexey Charkov
2010-11-09 7:36 ` Guennadi Liakhovetski
2010-11-09 9:39 ` Paul Mundt
2010-11-09 9:49 ` Alexey Charkov
2010-11-09 10:33 ` [PATCH 6/6 v3] " Russell King - ARM Linux
2010-11-09 10:51 ` Paul Mundt
2010-11-09 11:04 ` Russell King - ARM Linux
2010-11-09 13:02 ` Geert Uytterhoeven
2010-11-09 13:33 ` Arnd Bergmann
2010-11-09 16:20 ` Paul Mundt
2010-11-08 8:47 ` [PATCH 6/6 v2] " Arnd Bergmann
2010-11-09 10:23 ` Alexey Charkov
2010-11-09 15:03 ` Arnd Bergmann
2010-11-07 16:57 ` [PATCH 1/6 v2] ARM: Add basic architecture support for VIA/WonderMedia 85xx SoC's Russell King - ARM Linux
2010-11-07 17:08 ` Alexey Charkov
2010-11-07 17:17 ` Russell King - ARM Linux
2010-11-07 18:25 ` [PATCH 1/6 v3] " Alexey Charkov
2010-11-08 17:19 ` [PATCH 1/6 v4] " Alexey Charkov
2010-11-10 15:16 ` saeed bishara
2010-11-10 15:18 ` Russell King - ARM Linux
2010-11-10 15:20 ` saeed bishara
2010-11-11 21:23 ` [PATCH 1/6 v5] " Alexey Charkov
2010-11-11 23:49 ` Russell King - ARM Linux
2010-11-12 16:54 ` [PATCH 1/6 v6] " Alexey Charkov
2010-11-12 20:14 ` Alexey Charkov
2010-11-23 19:50 ` [PATCH 1/6 v7] " Alexey Charkov
2010-12-19 17:40 ` [PATCH 1/6 v8] " Alexey Charkov
2010-12-20 18:15 ` Arnd Bergmann
2010-12-20 19:15 ` Russell King - ARM Linux
2010-12-20 19:26 ` Alexey Charkov
2010-12-20 19:54 ` [PATCH 1/6 v9] " Alexey Charkov
2010-12-20 20:50 ` Ryan Mallon
2010-12-20 21:48 ` Alexey Charkov
2010-12-20 22:23 ` Ryan Mallon
2010-12-20 23:00 ` Alexey Charkov
2010-12-20 23:22 ` Ryan Mallon
2010-12-20 23:49 ` Alexey Charkov
2010-12-21 0:09 ` Alexey Charkov
2010-12-21 2:32 ` Ryan Mallon
2010-12-21 10:00 ` Alexey Charkov
2010-12-21 12:05 ` Arnd Bergmann
2010-12-21 19:39 ` Ryan Mallon
2010-12-22 21:18 ` [PATCH 1/6 v10] " Alexey Charkov
2010-12-22 21:52 ` Ryan Mallon
2010-12-22 22:02 ` Alexey Charkov
2010-12-22 22:32 ` Ryan Mallon
2010-12-22 22:25 ` [PATCH 1/6 v11] " Alexey Charkov
2010-12-22 22:59 ` Ryan Mallon
2010-12-22 23:38 ` [PATCH 1/6 v12] " Alexey Charkov
2010-12-28 14:52 ` Alexey Charkov
2011-01-15 0:53 ` Alexey Charkov
2011-01-15 0:58 ` Russell King - ARM Linux
2011-01-15 1:13 ` Alexey Charkov
2011-01-21 10:43 ` Russell King - ARM Linux
2011-07-06 12:34 ` [PATCH 1/6 v8] " Russell King - ARM Linux
2011-07-07 7:13 ` Alexey Charkov
2011-07-07 7:54 ` Arnd Bergmann
2011-07-07 7:59 ` Russell King - ARM Linux
2011-07-07 8:05 ` Arnd Bergmann
2010-11-07 17:00 ` [PATCH 1/6 v2] " Russell King - ARM Linux
2010-11-07 17:16 ` Alexey Charkov
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