| Message ID | 20180221175734.39114-1-Evgeniy.Didin@synopsys.com |
|---|---|
| State | New |
| Headers | show |
| Series | mmc: dw_mmc: Fix the DTO timeout overflow calculation for 32-bit systems | expand |
On Wed, Feb 21, 2018 at 7:57 PM, Evgeniy Didin <Evgeniy.Didin@synopsys.com> wrote: > In commit 9d9491a7da2a ("mmc: dw_mmc: Fix the DTO timeout calculation") have been made > changes which can cause multiply overflow for 32-bit systems. It was caught on arc/hsdk board > when "drto_ms" should be 671, but it was 70 and that caused a flow of stack-traces just copying > file from mmc. > > Lets cast this multiply to long long int which prevents overflow. > > Signed-off-by: Evgeniy Didin <Evgeniy.Didin@synopsys.com> > CC: Alexey Brodkin <abrodkin@synopsys.com> > CC: Douglas Anderson <dianders@chromium.org> > CC: Ulf Hansson <ulf.hansson@linaro.org> > CC: linux-kernel@vger.kernel.org > CC: linux-snps-arc@lists.infradead.org > --- a/drivers/mmc/host/dw_mmc.c > +++ b/drivers/mmc/host/dw_mmc.c > @@ -1944,7 +1944,7 @@ static void dw_mci_set_drto(struct dw_mci *host) > drto_div = (mci_readl(host, CLKDIV) & 0xff) * 2; > if (drto_div == 0) > drto_div = 1; > - drto_ms = DIV_ROUND_UP(MSEC_PER_SEC * drto_clks * drto_div, > + drto_ms = DIV_ROUND_UP((uint64_t)MSEC_PER_SEC * drto_clks * drto_div, > host->bus_hz); Does the driver use uint64_t elsewhere? Or simple u64?
Hi Evgeniy On 02/21/2018 09:57 AM, Evgeniy Didin wrote: > In commit 9d9491a7da2a ("mmc: dw_mmc: Fix the DTO timeout calculation") have been made > changes which can cause multiply overflow for 32-bit systems. Awesome, thx for quickly narrowing it down. I tried the fix and it cures my issue. It was caught on arc/hsdk board > when "drto_ms" should be 671, but it was 70 and that caused a flow of stack-traces just copying > file from mmc. IMHO, the fragment above could be improved. "The broken timeout calculations caused false interrupt latency warnings and stacktrace splat (such as below) when accessing the SD Card." | Running : 4M-check-reassembly-tcp-cmykw2-rotatew2.out -v0 -w1 | - Info: Finished target initialization. | mmcblk0: error -110 transferring data, sector 320544, nr 2048, cmd response | 0x900, card status 0x0 | mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 400000Hz, actual | 396825HZ div = 63) | mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 25000000Hz, actual | 25000000HZ div = 1) | ------------[ cut here ]------------ | softirq: huh, entered softirq 6 TASKLET 6f6a9412 with preempt_count 00000101, | exited with 00000100? | WARNING: CPU: 2 PID: 0 at ../lib/scatterlist.c:652 sg_miter_next+0x28/0x20c | Modules linked in: | CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.15.0 #57 | | Stack Trace: | arc_unwind_core.constprop.1+0xd0/0xf4 | dump_stack+0x68/0x80 | warn_slowpath_null+0x4e/0xec | sg_miter_next+0x28/0x20c | dw_mci_read_data_pio+0x44/0x190 | dw_mmc f000a000.mmc: Unexpected interrupt latency | dw_mci_interrupt+0x3ee/0x530 | __handle_irq_event_percpu+0x56/0x150 | handle_irq_event+0x34/0x78 | handle_level_irq+0x8e/0x120 | generic_handle_irq+0x1c/0x2c | idu_cascade_isr+0x30/0x6c | __handle_domain_irq+0x72/0xc8 | ret_from_exception+0x0/0x8 |---[ end trace 2a58c9af6c25fe51 ]--- > > Lets cast this multiply to long long int which prevents overflow. > > Signed-off-by: Evgeniy Didin <Evgeniy.Didin@synopsys.com> > CC: Alexey Brodkin <abrodkin@synopsys.com> > CC: Douglas Anderson <dianders@chromium.org> > CC: Ulf Hansson <ulf.hansson@linaro.org> > CC: linux-kernel@vger.kernel.org > CC: linux-snps-arc@lists.infradead.org Tested-by: Vineet Gupta <vgupta@synopsys.com> Fixes: ARC STAR 9001306872 HSDK, sdio: board crashes when copying big files > --- > drivers/mmc/host/dw_mmc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > index 0aa39975f33b..1a0b9751c67c 100644 > --- a/drivers/mmc/host/dw_mmc.c > +++ b/drivers/mmc/host/dw_mmc.c > @@ -1944,7 +1944,7 @@ static void dw_mci_set_drto(struct dw_mci *host) > drto_div = (mci_readl(host, CLKDIV) & 0xff) * 2; > if (drto_div == 0) > drto_div = 1; > - drto_ms = DIV_ROUND_UP(MSEC_PER_SEC * drto_clks * drto_div, > + drto_ms = DIV_ROUND_UP((uint64_t)MSEC_PER_SEC * drto_clks * drto_div, > host->bus_hz); > > /* add a bit spare time */ >
Hi Evgeniy,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on linus/master]
[also build test ERROR on v4.16-rc2 next-20180222]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Evgeniy-Didin/mmc-dw_mmc-Fix-the-DTO-timeout-overflow-calculation-for-32-bit-systems/20180223-054846
config: arm-exynos_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=arm
All errors (new ones prefixed by >>):
drivers/mmc/host/dw_mmc.o: In function `dw_mci_set_drto':
>> dw_mmc.c:(.text+0x1644): undefined reference to `__aeabi_uldivmod'
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
Hi Evgeniy,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on linus/master]
[also build test ERROR on v4.16-rc2 next-20180223]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Evgeniy-Didin/mmc-dw_mmc-Fix-the-DTO-timeout-overflow-calculation-for-32-bit-systems/20180223-054846
config: mips-pistachio_defconfig (attached as .config)
compiler: mipsel-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=mips
All errors (new ones prefixed by >>):
drivers/mmc/host/dw_mmc.o: In function `dw_mci_set_drto':
>> dw_mmc.c:(.text+0x176c): undefined reference to `__udivdi3'
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 0aa39975f33b..1a0b9751c67c 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -1944,7 +1944,7 @@ static void dw_mci_set_drto(struct dw_mci *host) drto_div = (mci_readl(host, CLKDIV) & 0xff) * 2; if (drto_div == 0) drto_div = 1; - drto_ms = DIV_ROUND_UP(MSEC_PER_SEC * drto_clks * drto_div, + drto_ms = DIV_ROUND_UP((uint64_t)MSEC_PER_SEC * drto_clks * drto_div, host->bus_hz); /* add a bit spare time */
In commit 9d9491a7da2a ("mmc: dw_mmc: Fix the DTO timeout calculation") have been made changes which can cause multiply overflow for 32-bit systems. It was caught on arc/hsdk board when "drto_ms" should be 671, but it was 70 and that caused a flow of stack-traces just copying file from mmc. Lets cast this multiply to long long int which prevents overflow. Signed-off-by: Evgeniy Didin <Evgeniy.Didin@synopsys.com> CC: Alexey Brodkin <abrodkin@synopsys.com> CC: Douglas Anderson <dianders@chromium.org> CC: Ulf Hansson <ulf.hansson@linaro.org> CC: linux-kernel@vger.kernel.org CC: linux-snps-arc@lists.infradead.org --- drivers/mmc/host/dw_mmc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)