From: joe@perches.com (Joe Perches)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] dmaengine: pl330: Fix linker error "undefined reference to `__aeabi_uldivmod'"
Date: Thu, 13 Nov 2014 10:28:44 -0800 [thread overview]
Message-ID: <1415903324.4223.5.camel@perches.com> (raw)
In-Reply-To: <1415902763.1787.8.camel@linaro.org>
On Thu, 2014-11-13 at 18:19 +0000, Jon Medhurst (Tixy) wrote:
> There are many ways to code the limiting of the burst width, but as it
> starts out as the data bus width the DMA can handle (maximum 16 bytes)
> then at most we'll be going round the existing while loop 4 times so I
> don't think it's that much overhead, and probably less code size than
> using ffs.
For arm, isn't ffs just a few instruction with no loops?
> And as the driver has been broken for the unaligned memcpy case since
> the day it was added then I can't see that anyone is actually using it
> that way anyway, so all existing users (if any) must already be doing
> bus aligned copies and the current while loop will iterate zero times.
That's probably right, I just don't like reading
while loops where ffs/fls might be suitable.
> That's probably enough bikeshedding from me :-)
;) Me too. cheers, Joe
WARNING: multiple messages have this Message-ID (diff)
From: Joe Perches <joe@perches.com>
To: "Jon Medhurst (Tixy)" <tixy@linaro.org>
Cc: Vinod Koul <vinod.koul@intel.com>,
dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] dmaengine: pl330: Fix linker error "undefined reference to `__aeabi_uldivmod'"
Date: Thu, 13 Nov 2014 10:28:44 -0800 [thread overview]
Message-ID: <1415903324.4223.5.camel@perches.com> (raw)
In-Reply-To: <1415902763.1787.8.camel@linaro.org>
On Thu, 2014-11-13 at 18:19 +0000, Jon Medhurst (Tixy) wrote:
> There are many ways to code the limiting of the burst width, but as it
> starts out as the data bus width the DMA can handle (maximum 16 bytes)
> then at most we'll be going round the existing while loop 4 times so I
> don't think it's that much overhead, and probably less code size than
> using ffs.
For arm, isn't ffs just a few instruction with no loops?
> And as the driver has been broken for the unaligned memcpy case since
> the day it was added then I can't see that anyone is actually using it
> that way anyway, so all existing users (if any) must already be doing
> bus aligned copies and the current while loop will iterate zero times.
That's probably right, I just don't like reading
while loops where ffs/fls might be suitable.
> That's probably enough bikeshedding from me :-)
;) Me too. cheers, Joe
next prev parent reply other threads:[~2014-11-13 18:28 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-13 16:27 [PATCH] dmaengine: pl330: Fix linker error "undefined reference to `__aeabi_uldivmod'" Jon Medhurst (Tixy)
2014-11-13 16:27 ` Jon Medhurst (Tixy)
2014-11-13 16:49 ` Arnd Bergmann
2014-11-13 16:49 ` Arnd Bergmann
2014-11-13 17:01 ` Vinod Koul
2014-11-13 17:01 ` Vinod Koul
2014-11-13 17:11 ` Jon Medhurst (Tixy)
2014-11-13 17:11 ` Jon Medhurst (Tixy)
2014-11-17 8:23 ` Vinod Koul
2014-11-17 8:23 ` Vinod Koul
2014-11-13 17:02 ` Joe Perches
2014-11-13 17:02 ` Joe Perches
2014-11-13 18:19 ` Jon Medhurst (Tixy)
2014-11-13 18:19 ` Jon Medhurst (Tixy)
2014-11-13 18:28 ` Joe Perches [this message]
2014-11-13 18:28 ` Joe Perches
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