From: Tero Kristo <t-kristo@ti.com> To: linux-omap@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, Paul Walmsley <paul@pwsan.com>, Benoit Cousson <b-cousson@ti.com>, Venkatraman S <svenkatr@ti.com> Subject: [RFC] ARM: OMAP: hwmod: wait for sysreset complete after enabling hwmod Date: Mon, 22 Oct 2012 19:15:32 +0300 [thread overview] Message-ID: <1350922532-26338-1-git-send-email-t-kristo@ti.com> (raw) When waking up from off-mode, some IP blocks are reset automatically by hardware. For this reason, software must wait until the reset has completed before attempting to access the IP block. This patch fixes for example the bug introduced by commit 6c31b2150ff96755d24e0ab6d6fea08a7bf5c44c ("mmc: omap_hsmmc: remove access to SYSCONFIG register"), in which the MMC IP block is reset during off-mode entry, but the code expects the module to be already available during the execution of context restore. Signed-off-by: Tero Kristo <t-kristo@ti.com> Cc: Paul Walmsley <paul@pwsan.com> Cc: Benoit Cousson <b-cousson@ti.com> Cc: Venkatraman S <svenkatr@ti.com> --- arch/arm/mach-omap2/omap_hwmod.c | 22 ++++++++++++++++++++++ 1 files changed, 22 insertions(+), 0 deletions(-) diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index b969ab1..523729b 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -1278,6 +1278,7 @@ static void _enable_sysc(struct omap_hwmod *oh) u8 idlemode, sf; u32 v; bool clkdm_act; + int c; if (!oh->class->sysc) return; @@ -1338,6 +1339,27 @@ static void _enable_sysc(struct omap_hwmod *oh) _set_module_autoidle(oh, idlemode, &v); _write_sysconfig(v, oh); } + + /* + * Wait until reset has completed, this is needed as the IP + * block is reset automatically by hardware in some cases + * (off-mode for example), and the drivers require the + * IP to be ready when they access it + */ + if (sf & SYSS_HAS_RESET_STATUS) + omap_test_timeout((omap_hwmod_read(oh, + oh->class->sysc->syss_offs) + & SYSS_RESETDONE_MASK), + MAX_MODULE_SOFTRESET_WAIT, c); + + if (sf & SYSC_HAS_RESET_STATUS) { + u32 softrst_mask = + (0x1 << oh->class->sysc->sysc_fields->srst_shift); + omap_test_timeout(!(omap_hwmod_read(oh, + oh->class->sysc->sysc_offs) + & softrst_mask), + MAX_MODULE_SOFTRESET_WAIT, c); + } } /** -- 1.7.4.1
WARNING: multiple messages have this Message-ID (diff)
From: t-kristo@ti.com (Tero Kristo) To: linux-arm-kernel@lists.infradead.org Subject: [RFC] ARM: OMAP: hwmod: wait for sysreset complete after enabling hwmod Date: Mon, 22 Oct 2012 19:15:32 +0300 [thread overview] Message-ID: <1350922532-26338-1-git-send-email-t-kristo@ti.com> (raw) When waking up from off-mode, some IP blocks are reset automatically by hardware. For this reason, software must wait until the reset has completed before attempting to access the IP block. This patch fixes for example the bug introduced by commit 6c31b2150ff96755d24e0ab6d6fea08a7bf5c44c ("mmc: omap_hsmmc: remove access to SYSCONFIG register"), in which the MMC IP block is reset during off-mode entry, but the code expects the module to be already available during the execution of context restore. Signed-off-by: Tero Kristo <t-kristo@ti.com> Cc: Paul Walmsley <paul@pwsan.com> Cc: Benoit Cousson <b-cousson@ti.com> Cc: Venkatraman S <svenkatr@ti.com> --- arch/arm/mach-omap2/omap_hwmod.c | 22 ++++++++++++++++++++++ 1 files changed, 22 insertions(+), 0 deletions(-) diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index b969ab1..523729b 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -1278,6 +1278,7 @@ static void _enable_sysc(struct omap_hwmod *oh) u8 idlemode, sf; u32 v; bool clkdm_act; + int c; if (!oh->class->sysc) return; @@ -1338,6 +1339,27 @@ static void _enable_sysc(struct omap_hwmod *oh) _set_module_autoidle(oh, idlemode, &v); _write_sysconfig(v, oh); } + + /* + * Wait until reset has completed, this is needed as the IP + * block is reset automatically by hardware in some cases + * (off-mode for example), and the drivers require the + * IP to be ready when they access it + */ + if (sf & SYSS_HAS_RESET_STATUS) + omap_test_timeout((omap_hwmod_read(oh, + oh->class->sysc->syss_offs) + & SYSS_RESETDONE_MASK), + MAX_MODULE_SOFTRESET_WAIT, c); + + if (sf & SYSC_HAS_RESET_STATUS) { + u32 softrst_mask = + (0x1 << oh->class->sysc->sysc_fields->srst_shift); + omap_test_timeout(!(omap_hwmod_read(oh, + oh->class->sysc->sysc_offs) + & softrst_mask), + MAX_MODULE_SOFTRESET_WAIT, c); + } } /** -- 1.7.4.1
next reply other threads:[~2012-10-22 16:15 UTC|newest] Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-10-22 16:15 Tero Kristo [this message] 2012-10-22 16:15 ` [RFC] ARM: OMAP: hwmod: wait for sysreset complete after enabling hwmod Tero Kristo 2012-10-22 21:46 ` Kevin Hilman 2012-10-22 21:46 ` Kevin Hilman 2012-10-23 15:43 ` Shubhrajyoti Datta 2012-10-23 15:43 ` Shubhrajyoti Datta 2012-10-23 16:09 ` Kevin Hilman 2012-10-23 16:09 ` Kevin Hilman 2012-10-23 17:50 ` Shubhrajyoti Datta 2012-10-23 17:50 ` Shubhrajyoti Datta 2012-10-23 7:47 ` Paul Walmsley 2012-10-23 7:47 ` Paul Walmsley 2012-10-23 8:03 ` Tero Kristo 2012-10-23 8:03 ` Tero Kristo 2012-10-30 3:11 ` Paul Walmsley 2012-10-30 3:11 ` Paul Walmsley 2012-10-23 14:28 ` Kevin Hilman 2012-10-23 14:28 ` Kevin Hilman 2012-10-23 14:49 ` Santosh Shilimkar 2012-10-23 14:49 ` Santosh Shilimkar 2012-10-23 17:03 ` Kevin Hilman 2012-10-23 17:03 ` Kevin Hilman
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