From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tero Kristo Subject: Re: [PATCHv4 16/33] CLK: OMAP: DPLL: do not of_iomap NULL autoidle register Date: Wed, 31 Jul 2013 17:57:56 +0300 Message-ID: <51F925F4.2000308@ti.com> References: <1374564028-11352-1-git-send-email-t-kristo@ti.com> <1374564028-11352-17-git-send-email-t-kristo@ti.com> <51F818CB.4060007@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <51F818CB.4060007@ti.com> Sender: linux-omap-owner@vger.kernel.org To: Nishanth Menon Cc: linux-omap@vger.kernel.org, paul@pwsan.com, khilman@linaro.org, tony@atomide.com, mturquette@linaro.org, rnayak@ti.com, linux-arm-kernel@lists.infradead.org, devicetree-discuss@lists.ozlabs.org List-Id: devicetree@vger.kernel.org On 07/30/2013 10:49 PM, Nishanth Menon wrote: > On 07/23/2013 02:20 AM, Tero Kristo wrote: >> AM33xx series SoCs do not have autoidle support, and for these the >> autoidle register is marked as NULL. Check against a NULL pointer and >> do not attempt to of_iomap in this case, as this just creates a bogus >> pointer and causes a kernel crash during boot. >> >> Signed-off-by: Tero Kristo >> --- >> drivers/clk/omap/dpll.c | 10 +++++++++- >> 1 file changed, 9 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/clk/omap/dpll.c b/drivers/clk/omap/dpll.c >> index 1d24feada..d8a958a 100644 >> --- a/drivers/clk/omap/dpll.c >> +++ b/drivers/clk/omap/dpll.c >> @@ -162,6 +162,7 @@ static void __init of_omap_dpll_setup(struct >> device_node *node, >> u32 max_multiplier = 2047; >> u32 max_divider = 128; >> u32 min_divider = 1; >> + u32 val; >> int i; >> >> dd = kzalloc(sizeof(struct dpll_data), GFP_KERNEL); >> @@ -210,7 +211,14 @@ static void __init of_omap_dpll_setup(struct >> device_node *node, >> >> dd->control_reg = of_iomap(node, 0); >> dd->idlest_reg = of_iomap(node, 1); >> - dd->autoidle_reg = of_iomap(node, 2); >> + /* >> + * AM33xx DPLLs have no autoidle support, and the autoidle reg >> + * for these is NULL. Do not attempt to of_iomap in this case, >> + * as this just creates a bogus pointer and crashes the kernel. >> + */ >> + of_property_read_u32_index(node, "reg", 2 * 2, &val); >> + if (val) >> + dd->autoidle_reg = of_iomap(node, 2); > should we not do that for all the parameters? Maybe do the check for all. > OR: > move this as index 3 which is optional and is not defined for am33xx? > >> dd->mult_div1_reg = of_iomap(node, 3); > >> >> dd->idlest_mask = idlest_mask; >> > we could probably squash this in original dpll.c as a result? > Yea, can do that also. From mboxrd@z Thu Jan 1 00:00:00 1970 From: t-kristo@ti.com (Tero Kristo) Date: Wed, 31 Jul 2013 17:57:56 +0300 Subject: [PATCHv4 16/33] CLK: OMAP: DPLL: do not of_iomap NULL autoidle register In-Reply-To: <51F818CB.4060007@ti.com> References: <1374564028-11352-1-git-send-email-t-kristo@ti.com> <1374564028-11352-17-git-send-email-t-kristo@ti.com> <51F818CB.4060007@ti.com> Message-ID: <51F925F4.2000308@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/30/2013 10:49 PM, Nishanth Menon wrote: > On 07/23/2013 02:20 AM, Tero Kristo wrote: >> AM33xx series SoCs do not have autoidle support, and for these the >> autoidle register is marked as NULL. Check against a NULL pointer and >> do not attempt to of_iomap in this case, as this just creates a bogus >> pointer and causes a kernel crash during boot. >> >> Signed-off-by: Tero Kristo >> --- >> drivers/clk/omap/dpll.c | 10 +++++++++- >> 1 file changed, 9 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/clk/omap/dpll.c b/drivers/clk/omap/dpll.c >> index 1d24feada..d8a958a 100644 >> --- a/drivers/clk/omap/dpll.c >> +++ b/drivers/clk/omap/dpll.c >> @@ -162,6 +162,7 @@ static void __init of_omap_dpll_setup(struct >> device_node *node, >> u32 max_multiplier = 2047; >> u32 max_divider = 128; >> u32 min_divider = 1; >> + u32 val; >> int i; >> >> dd = kzalloc(sizeof(struct dpll_data), GFP_KERNEL); >> @@ -210,7 +211,14 @@ static void __init of_omap_dpll_setup(struct >> device_node *node, >> >> dd->control_reg = of_iomap(node, 0); >> dd->idlest_reg = of_iomap(node, 1); >> - dd->autoidle_reg = of_iomap(node, 2); >> + /* >> + * AM33xx DPLLs have no autoidle support, and the autoidle reg >> + * for these is NULL. Do not attempt to of_iomap in this case, >> + * as this just creates a bogus pointer and crashes the kernel. >> + */ >> + of_property_read_u32_index(node, "reg", 2 * 2, &val); >> + if (val) >> + dd->autoidle_reg = of_iomap(node, 2); > should we not do that for all the parameters? Maybe do the check for all. > OR: > move this as index 3 which is optional and is not defined for am33xx? > >> dd->mult_div1_reg = of_iomap(node, 3); > >> >> dd->idlest_mask = idlest_mask; >> > we could probably squash this in original dpll.c as a result? > Yea, can do that also.