[U-Boot] [PATCH] ARM: fix write*() I/O accessors

Albert ARIBAUD albert.aribaud at free.fr
Fri Feb 11 23:31:37 CET 2011


Le 11/02/2011 23:25, Wolfgang Denk a écrit :
> Commit 3c0659b "ARM: Avoid compiler optimization for readb, writeb
> and friends." introduced I/O accessors with memory barriers.
> Unfortunately the new write*() accessors introduced a bug:
>
> The problem is that the argument "v" gets evaluated twice.  This
> breaks code like used here (from "drivers/net/dnet.c"):
>
> 	for (i = 0; i<  wrsz; i++)
> 		writel(*bufp++,&dnet->regs->TX_DATA_FIFO);
>
> Use auxiliary variables to avoid such problems.
>
> Signed-off-by: Wolfgang Denk<wd at denx.de>
> Cc: Albert Aribaud<albert.aribaud at free.fr>
> Cc: Alexander Holler<holler at ahsoftware.de>
> Cc: Dirk Behme<dirk.behme at googlemail.com>
> ---
>
> This patch fixes a pretty nasty problem.  Everybody who has
> experienced strange failures on ARM lately should apply it ASAP and
> re-test.  As far as I can tell at least the following drivers are
> affected:
>
> drivers/net/dnet.c:		writel(*bufp++,&dnet->regs->TX_DATA_FIFO);
> drivers/usb/musb/musb_core.c:	writeb(*data++,&musbr->fifox[ep]);
> drivers/mmc/pxa_mmc.c:		writel(*src++, MMC_TXFIFO);
> drivers/mmc/mxcmmc.c:		writel(*buf++,&host->base->buffer_access);
> drivers/spi/davinci_spi.c:	writel(data1_reg_val | *txp++,&ds->regs->dat1);
>
> Albert, please apply ASAP!

Applied, available on u-boot-arm/master.

Amicalement,
-- 
Albert.


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