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From: Timur Tabi <timur@freescale.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [u-boot-release] [RFC PATCH 17/17] ns16550: wait for TENT before initializing
Date: Mon, 1 Oct 2012 09:27:15 -0500	[thread overview]
Message-ID: <5069A843.80504@freescale.com> (raw)
In-Reply-To: <1348272087-29608-18-git-send-email-scottwood@freescale.com>

Scott Wood wrote:
> This prevents output problems (including a loss of synchronization
> observed on p2020 that persisted for quite a while) if SPL has output
> still on its way out.  I'm not sure why this is only now beginning to
> happen, though.

The subject line says "TENT", but the macro says "TEMT".

Also, it would be nice to see a description of this bit somewhere.

> 
> Signed-off-by: Scott Wood <scottwood@freescale.com>
> ---
>  drivers/serial/ns16550.c |    3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
> index 0c23955..66201b6 100644
> --- a/drivers/serial/ns16550.c
> +++ b/drivers/serial/ns16550.c
> @@ -36,6 +36,9 @@
>  
>  void NS16550_init(NS16550_t com_port, int baud_divisor)
>  {
> +	while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
> +		;
> +
>  	serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
>  #if (defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)) || \
>  					defined(CONFIG_AM33XX)


-- 
Timur Tabi
Linux kernel developer at Freescale

  reply	other threads:[~2012-10-01 14:27 UTC|newest]

Thread overview: 81+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-22  0:01 [U-Boot] [RFC PATCH 00/17] Convert p1_p2_rdb_pc to new spl Scott Wood
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 01/17] Add u-boot-pad.bin target to the Makefile Scott Wood
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 02/17] spl: rename u-boot-pad.bin to u-boot-with-spl.bin Scott Wood
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 03/17] powerpc: remove .fixup test Scott Wood
2012-09-24 15:30   ` Peter Tyser
2012-09-24 18:47     ` Scott Wood
2012-09-24 23:38       ` Tom Rini
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 04/17] powerpc/mpc85xx: fix TLB alignment Scott Wood
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 05/17] powerpc/mpc8xxx: move LAW code into arch/powerpc/cpu/mpc8xxx Scott Wood
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 06/17] spl/mpc85xx: move udelay to cpu code Scott Wood
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 07/17] spl: include resetvec and lib8xxx Scott Wood
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 08/17] spl/powerpc: introduce CONFIG_SPL_INIT_MINIMAL Scott Wood
2012-09-24 23:48   ` Tom Rini
2012-09-24 23:52     ` Scott Wood
2012-09-25  0:03       ` Tom Rini
2012-09-25  0:17         ` Scott Wood
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 09/17] spl/85xx: new SPL support Scott Wood
2012-09-24 23:51   ` Tom Rini
2012-09-24 23:54     ` Scott Wood
2012-09-25  0:04       ` Tom Rini
2012-09-25  0:08         ` Scott Wood
2012-09-25  0:13           ` Tom Rini
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 10/17] powerpc/p1_p2_rdb_pc: " Scott Wood
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 11/17] spl/nand: introduce CONFIG_SPL_NAND_MINIMAL Scott Wood
2012-09-24 23:55   ` Tom Rini
2012-09-25  0:02     ` Scott Wood
2012-09-25  0:13       ` Tom Rini
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 12/17] spl/nand: config symbol documentation Scott Wood
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 13/17] spl/nand: Add minimal-spl driver for Freescale eLBC NAND Scott Wood
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 14/17] spl: introduce CONFIG_SPL_TARGET Scott Wood
2012-09-22  0:12   ` Tom Rini
2012-09-24 18:54     ` Scott Wood
2012-09-24 19:03       ` Tom Rini
2012-09-24 20:05         ` Scott Wood
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 15/17] p1_p2_rdb_pc: convert from nand_spl to new spl Scott Wood
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 16/17] powerpc/mpc85xx/p2020rdb-pc: fix SPL DDR config Scott Wood
2012-09-22  0:01 ` [U-Boot] [RFC PATCH 17/17] ns16550: wait for TENT before initializing Scott Wood
2012-10-01 14:27   ` Timur Tabi [this message]
2012-09-22  0:13 ` [U-Boot] [RFC PATCH 00/17] Convert p1_p2_rdb_pc to new spl Tom Rini
2012-09-24 18:50   ` Scott Wood
2012-09-24 19:06     ` Tom Rini
2012-09-24 19:15       ` Scott Wood
2012-10-30  2:04 ` [U-Boot] [PATCH v2 00/22] " Scott Wood
2012-10-30  2:04   ` [U-Boot] [PATCH v2 01/22] serial/ns16550: don't build serial_ns16550 with MIN_FUNCTIONS Scott Wood
2012-10-30  2:04   ` [U-Boot] [PATCH v2 02/22] serial/ns16550: wait for TEMT before initializing Scott Wood
2012-10-30  2:04   ` [U-Boot] [PATCH v2 03/22] powerpc/mpc85xx: move debug tlb entry after TLB is in known state Scott Wood
2012-10-30  9:26     ` Prabhakar Kushwaha
2012-10-30 21:07       ` Scott Wood
2012-10-31  6:17         ` Prabhakar Kushwaha
2012-10-31 22:08           ` Scott Wood
2012-10-31 22:44             ` McClintock Matthew-B29882
     [not found]             ` <CAEsOVNeZAyH1nxfgnjPYUG4=7yxjF9rjsRWrpa=WYW8edfiM3Q@mail.gmail.com>
2012-10-31 22:45               ` McClintock Matthew-B29882
2012-10-31 22:51                 ` Scott Wood
2012-11-16  2:12     ` Scott Wood
2012-11-26 20:53     ` Andy Fleming
2012-10-30  2:04   ` [U-Boot] [PATCH v2 04/22] powerpc/mpc85xx: add comma before "already enabled" Scott Wood
2012-10-30  2:04   ` [U-Boot] [PATCH v2 05/22] Add u-boot-pad.bin target to the Makefile Scott Wood
2012-10-30  2:04   ` [U-Boot] [PATCH v2 06/22] spl: rename u-boot-pad.bin to u-boot-with-spl.bin Scott Wood
2012-10-30  2:04   ` [U-Boot] [PATCH v2 07/22] spl: introduce CONFIG_SPL_TARGET Scott Wood
2012-10-30  2:04   ` [U-Boot] [PATCH v2 08/22] powerpc: change .fixup test to a GCC version test Scott Wood
2012-10-30  2:04   ` [U-Boot] [PATCH v2 09/22] powerpc/mpc85xx: fix TLB alignment Scott Wood
2012-10-30  2:04   ` [U-Boot] [PATCH v2 10/22] powerpc/mpc8xxx: move LAW code into arch/powerpc/cpu/mpc8xxx Scott Wood
2012-10-30  2:04   ` [U-Boot] [PATCH v2 11/22] spl/mpc85xx: move udelay to cpu code Scott Wood
2012-10-30  2:05   ` [U-Boot] [PATCH v2 12/22] spl: include resetvec and lib8xxx Scott Wood
2012-10-30  2:05   ` [U-Boot] [PATCH v2 13/22] spl/mpc85xx: rename cpu_init_nand.c to spl_minimal.c Scott Wood
2012-10-30  2:05   ` [U-Boot] [PATCH v2 14/22] powerpc/mpc85xx: consistently use COBJS-y Scott Wood
2012-10-30  2:05   ` [U-Boot] [PATCH v2 15/22] spl/powerpc: introduce CONFIG_SPL_INIT_MINIMAL Scott Wood
2012-10-30  2:05   ` [U-Boot] [PATCH v2 16/22] spl/85xx: new SPL support Scott Wood
2012-10-30  2:05   ` [U-Boot] [PATCH v2 17/22] powerpc/mpc85xx/p1_p2_rdb_pc: " Scott Wood
2012-10-30  2:05   ` [U-Boot] [PATCH v2 18/22] spl/nand: introduce CONFIG_SPL_NAND_DRIVERS, _BASE, and _ECC Scott Wood
2012-10-30  2:05   ` [U-Boot] [PATCH v2 19/22] spl/nand: config symbol documentation Scott Wood
2012-10-30  2:05   ` [U-Boot] [PATCH v2 20/22] powerpc/mpc85xx/p1_p2_rdb_pc: convert from nand_spl to new spl Scott Wood
2012-10-30  2:05   ` [U-Boot] [PATCH v2 21/22] powerpc/mpc85xx/p1_p2_rdb_pc: clean up memory map Scott Wood
2012-10-30  2:05   ` [U-Boot] [PATCH v2 22/22] powerpc/mpc85xx/p2020rdb-pca: Use L2 SRAM for SPL boot Scott Wood
2012-10-30  3:17     ` Tabi Timur-B04825
2012-10-30 23:37       ` Scott Wood
2012-11-13 22:41     ` [U-Boot] [PATCH v3] " Scott Wood
2012-10-30 17:04   ` [U-Boot] [PATCH v2 00/22] Convert p1_p2_rdb_pc to new spl Tom Rini
2012-10-30 20:17     ` Scott Wood
2012-10-30 21:12       ` Tom Rini
2012-11-13 22:42         ` Scott Wood

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