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* [PATCH AUTOSEL for 4.14 01/60] backlight: pwm_bl: Fix overflow condition
@ 2017-12-13  1:55 alexander.levin
  2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 03/60] clk: sunxi-ng: nm: Check if requested rate is supported by fractional clock alexander.levin
                   ` (46 more replies)
  0 siblings, 47 replies; 53+ messages in thread
From: alexander.levin @ 2017-12-13  1:55 UTC (permalink / raw)
  To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
  Cc: Derek Basehore, Lee Jones, alexander.levin

From: Derek Basehore <dbasehore@chromium.org>

[ Upstream commit 5d0c49acebc9488e37db95f1d4a55644e545ffe7 ]

This fixes an overflow condition that can happen with high max
brightness and period values in compute_duty_cycle. This fixes it by
using a 64 bit variable for computing the duty cycle.

Signed-off-by: Derek Basehore <dbasehore@chromium.org>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
---
 drivers/video/backlight/pwm_bl.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 9bd17682655a..1c2289ddd555 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -79,14 +79,17 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb)
 static int compute_duty_cycle(struct pwm_bl_data *pb, int brightness)
 {
 	unsigned int lth = pb->lth_brightness;
-	int duty_cycle;
+	u64 duty_cycle;
 
 	if (pb->levels)
 		duty_cycle = pb->levels[brightness];
 	else
 		duty_cycle = brightness;
 
-	return (duty_cycle * (pb->period - lth) / pb->scale) + lth;
+	duty_cycle *= pb->period - lth;
+	do_div(duty_cycle, pb->scale);
+
+	return duty_cycle + lth;
 }
 
 static int pwm_backlight_update_status(struct backlight_device *bl)
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 53+ messages in thread

end of thread, other threads:[~2017-12-20 17:13 UTC | newest]

Thread overview: 53+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-12-13  1:55 [PATCH AUTOSEL for 4.14 01/60] backlight: pwm_bl: Fix overflow condition alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 03/60] clk: sunxi-ng: nm: Check if requested rate is supported by fractional clock alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 02/60] drm: Add retries for lspcon mode detection alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 05/60] crypto: talitos - fix ctr-aes-talitos alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 04/60] clk: sunxi-ng: sun5i: Fix bit offset of audio PLL post-divider alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 07/60] crypto: talitos - fix memory corruption on SEC2 alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 06/60] crypto: talitos - fix AEAD test failures alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 10/60] rtc: pl031: make interrupt optional alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 09/60] crypto: lrw - Fix an error handling path in 'create()' alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 11/60] kvm, mm: account kvm related kmem slabs to kmemcg alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 12/60] net: phy: at803x: Change error to EINVAL for invalid MAC alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 14/60] scsi: cxgb4i: fix Tx skb leak alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 13/60] PCI: Avoid bus reset if bridge itself is broken alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 15/60] scsi: mpt3sas: Fix IO error occurs on pulling out a drive from RAID1 volume created on two SATA drive alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 17/60] PM / OPP: Move error message to debug level alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 18/60] igb: check memory allocation failure alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 19/60] Bluetooth: avoid silent hci_bcm ACPI PM regression alexander.levin
2017-12-13  8:14   ` Johan Hovold
2017-12-13 13:37     ` alexander.levin
2017-12-13 14:05       ` Johan Hovold
2017-12-13 14:18         ` alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 20/60] kbuild: re-order the code to not parse unnecessary variables alexander.levin
2017-12-20 17:13   ` Greg KH
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 21/60] i40e: use the safe hash table iterator when deleting mac filters alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 26/60] md: always set THREAD_WAKEUP and wake up wqueue if thread existed alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 24/60] IB/rxe: check for allocation failure on elem alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 23/60] ixgbe: fix use of uninitialized padding alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 28/60] ipv6: grab rt->rt6i_ref before allocating pcpu rt alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 30/60] Bluetooth: hci_uart_set_flow_control: Fix NULL deref when using serdev alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 32/60] i40e/i40evf: spread CPU affinity hints across online CPUs only alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 31/60] Bluetooth: hci_bcm: Fix setting of irq trigger type alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 33/60] PCI/AER: Report non-fatal errors only to the affected endpoint alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 34/60] tracing: Exclude 'generic fields' from histograms alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 35/60] percpu: don't forget to free the temporary struct pcpu_alloc_info alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 37/60] ASoC: img-parallel-out: Add pm_runtime_get/put to set_fmt callback alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 36/60] ASoC: codecs: msm8916-wcd-analog: fix micbias level alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 41/60] ASoC: codecs: msm8916-wcd-analog: fix module autoload alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 42/60] fm10k: fix mis-ordered parameters in declaration for .ndo_set_vf_bw alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 46/60] i40e: fix client notify of VF reset alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 45/60] scsi: lpfc: Fix warning messages when NVME_TARGET_FC not defined alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 44/60] scsi: lpfc: PLOGI failures during NPIV testing alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 43/60] scsi: lpfc: Fix secure firmware updates alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 47/60] vfio/pci: Virtualize Maximum Payload Size alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 48/60] ARM: exynos_defconfig: Enable UAS support for Odroid HC1 board alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 50/60] ibmvnic: Set state UP alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 49/60] fm10k: ensure we process SM mbx when processing VF mbx alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 52/60] RDMA/hns: Avoid NULL pointer exception alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 51/60] net: ipv6: send NS for DAD when link operationally up alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 54/60] clk: sunxi-ng: sun6i: Rename HDMI DDC clock to avoid name collision alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 58/60] drm/vc4: Avoid using vrefresh==0 mode in DSI htotal math alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 56/60] rtc: set the alarm to the next expiring timer alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 60/60] IB/opa_vnic: Properly return the total MACs in UC MAC list alexander.levin
2017-12-13  1:55 ` [PATCH AUTOSEL for 4.14 59/60] IB/opa_vnic: Properly clear Mac Table Digest alexander.levin

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