* [REPOST PATCH] drm/msm: Set dma maximum segment size for mdss
@ 2020-01-21 19:18 Douglas Anderson
2020-01-21 19:26 ` Rob Clark
0 siblings, 1 reply; 5+ messages in thread
From: Douglas Anderson @ 2020-01-21 19:18 UTC (permalink / raw)
To: Rob Clark
Cc: saiprakash.ranjan, mka, Stephen Boyd, Sean Paul,
Douglas Anderson, Sean Paul, linux-arm-msm, linux-kernel,
dri-devel, David Airlie, freedreno, Daniel Vetter
From: Sean Paul <seanpaul@chromium.org>
Turning on CONFIG_DMA_API_DEBUG_SG results in the following error:
[ 12.078665] msm ae00000.mdss: DMA-API: mapping sg segment longer than device claims to support [len=3526656] [max=65536]
[ 12.089870] WARNING: CPU: 6 PID: 334 at /mnt/host/source/src/third_party/kernel/v4.19/kernel/dma/debug.c:1301 debug_dma_map_sg+0x1dc/0x318
[ 12.102655] Modules linked in: joydev
[ 12.106442] CPU: 6 PID: 334 Comm: frecon Not tainted 4.19.0 #2
[ 12.112450] Hardware name: Google Cheza (rev3+) (DT)
[ 12.117566] pstate: 60400009 (nZCv daif +PAN -UAO)
[ 12.122506] pc : debug_dma_map_sg+0x1dc/0x318
[ 12.126995] lr : debug_dma_map_sg+0x1dc/0x318
[ 12.131487] sp : ffffff800cc3ba80
[ 12.134913] x29: ffffff800cc3ba80 x28: 0000000000000000
[ 12.140395] x27: 0000000000000004 x26: 0000000000000004
[ 12.145868] x25: ffffff8008e55b18 x24: 0000000000000000
[ 12.151337] x23: 00000000ffffffff x22: ffffff800921c000
[ 12.156809] x21: ffffffc0fa75b080 x20: ffffffc0f7195090
[ 12.162280] x19: ffffffc0f1c53280 x18: 0000000000000000
[ 12.167749] x17: 0000000000000000 x16: 0000000000000000
[ 12.173218] x15: 0000000000000000 x14: 0720072007200720
[ 12.178689] x13: 0720072007200720 x12: 0720072007200720
[ 12.184161] x11: 0720072007200720 x10: 0720072007200720
[ 12.189641] x9 : ffffffc0f1fc6b60 x8 : 0000000000000000
[ 12.195110] x7 : ffffff8008132ce0 x6 : 0000000000000000
[ 12.200585] x5 : 0000000000000000 x4 : ffffff8008134734
[ 12.206058] x3 : ffffff800cc3b830 x2 : ffffffc0f1fc6240
[ 12.211532] x1 : 25045a74f48a7400 x0 : 25045a74f48a7400
[ 12.217006] Call trace:
[ 12.219535] debug_dma_map_sg+0x1dc/0x318
[ 12.223671] get_pages+0x19c/0x20c
[ 12.227177] msm_gem_fault+0x64/0xfc
[ 12.230874] __do_fault+0x3c/0x140
[ 12.234383] __handle_mm_fault+0x70c/0xdb8
[ 12.238603] handle_mm_fault+0xac/0xc4
[ 12.242473] do_page_fault+0x1bc/0x3d4
[ 12.246342] do_translation_fault+0x54/0x88
[ 12.250652] do_mem_abort+0x60/0xf0
[ 12.254250] el0_da+0x20/0x24
[ 12.257317] irq event stamp: 67260
[ 12.260828] hardirqs last enabled at (67259): [<ffffff8008132d0c>] console_unlock+0x214/0x608
[ 12.269693] hardirqs last disabled at (67260): [<ffffff8008080e0c>] do_debug_exception+0x5c/0x178
[ 12.278820] softirqs last enabled at (67256): [<ffffff8008081664>] __do_softirq+0x4d4/0x520
[ 12.287510] softirqs last disabled at (67249): [<ffffff80080be574>] irq_exit+0xa8/0x100
[ 12.295742] ---[ end trace e63cfc40c313ffab ]---
The root of the problem is that the default segment size for sgt is
(UINT_MAX & PAGE_MASK), and the default segment size for device dma is
64K. As such, if you compare the 2, you would deduce that the sg segment
will overflow the device's capacity. In reality, the hardware can
accommodate the larger sg segments, it's just not initializing its max
segment properly. This patch initializes the max segment size for the
mdss device, which gets rid of that pesky warning.
Reported-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Tested-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
This patch has been floating in the ether for over a year [1]. I know
next to nothing about it, but I'm told it's still useful so I'm
helpfully reposting it. Please enjoy.
[1] https://lore.kernel.org/r/20181106213239.52133-1-sean@poorly.run
drivers/gpu/drm/msm/msm_drv.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index c26219c7a49f..e4b750b0c2d3 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -441,6 +441,14 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
if (ret)
goto err_msm_uninit;
+ if (!dev->dma_parms) {
+ dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
+ GFP_KERNEL);
+ if (!dev->dma_parms)
+ return -ENOMEM;
+ }
+ dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
+
msm_gem_shrinker_init(ddev);
switch (get_mdp_ver(pdev)) {
--
2.25.0.341.g760bfbb309-goog
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [REPOST PATCH] drm/msm: Set dma maximum segment size for mdss
2020-01-21 19:18 [REPOST PATCH] drm/msm: Set dma maximum segment size for mdss Douglas Anderson
@ 2020-01-21 19:26 ` Rob Clark
2020-01-22 14:14 ` Sai Prakash Ranjan
2020-01-22 14:51 ` Sean Paul
0 siblings, 2 replies; 5+ messages in thread
From: Rob Clark @ 2020-01-21 19:26 UTC (permalink / raw)
To: Douglas Anderson
Cc: saiprakash.ranjan, Matthias Kaehlcke, Stephen Boyd, Sean Paul,
Sean Paul, linux-arm-msm, Linux Kernel Mailing List, dri-devel,
David Airlie, freedreno, Daniel Vetter
On Tue, Jan 21, 2020 at 11:19 AM Douglas Anderson <dianders@chromium.org> wrote:
>
> From: Sean Paul <seanpaul@chromium.org>
>
> Turning on CONFIG_DMA_API_DEBUG_SG results in the following error:
>
> [ 12.078665] msm ae00000.mdss: DMA-API: mapping sg segment longer than device claims to support [len=3526656] [max=65536]
> [ 12.089870] WARNING: CPU: 6 PID: 334 at /mnt/host/source/src/third_party/kernel/v4.19/kernel/dma/debug.c:1301 debug_dma_map_sg+0x1dc/0x318
> [ 12.102655] Modules linked in: joydev
> [ 12.106442] CPU: 6 PID: 334 Comm: frecon Not tainted 4.19.0 #2
> [ 12.112450] Hardware name: Google Cheza (rev3+) (DT)
> [ 12.117566] pstate: 60400009 (nZCv daif +PAN -UAO)
> [ 12.122506] pc : debug_dma_map_sg+0x1dc/0x318
> [ 12.126995] lr : debug_dma_map_sg+0x1dc/0x318
> [ 12.131487] sp : ffffff800cc3ba80
> [ 12.134913] x29: ffffff800cc3ba80 x28: 0000000000000000
> [ 12.140395] x27: 0000000000000004 x26: 0000000000000004
> [ 12.145868] x25: ffffff8008e55b18 x24: 0000000000000000
> [ 12.151337] x23: 00000000ffffffff x22: ffffff800921c000
> [ 12.156809] x21: ffffffc0fa75b080 x20: ffffffc0f7195090
> [ 12.162280] x19: ffffffc0f1c53280 x18: 0000000000000000
> [ 12.167749] x17: 0000000000000000 x16: 0000000000000000
> [ 12.173218] x15: 0000000000000000 x14: 0720072007200720
> [ 12.178689] x13: 0720072007200720 x12: 0720072007200720
> [ 12.184161] x11: 0720072007200720 x10: 0720072007200720
> [ 12.189641] x9 : ffffffc0f1fc6b60 x8 : 0000000000000000
> [ 12.195110] x7 : ffffff8008132ce0 x6 : 0000000000000000
> [ 12.200585] x5 : 0000000000000000 x4 : ffffff8008134734
> [ 12.206058] x3 : ffffff800cc3b830 x2 : ffffffc0f1fc6240
> [ 12.211532] x1 : 25045a74f48a7400 x0 : 25045a74f48a7400
> [ 12.217006] Call trace:
> [ 12.219535] debug_dma_map_sg+0x1dc/0x318
> [ 12.223671] get_pages+0x19c/0x20c
> [ 12.227177] msm_gem_fault+0x64/0xfc
> [ 12.230874] __do_fault+0x3c/0x140
> [ 12.234383] __handle_mm_fault+0x70c/0xdb8
> [ 12.238603] handle_mm_fault+0xac/0xc4
> [ 12.242473] do_page_fault+0x1bc/0x3d4
> [ 12.246342] do_translation_fault+0x54/0x88
> [ 12.250652] do_mem_abort+0x60/0xf0
> [ 12.254250] el0_da+0x20/0x24
> [ 12.257317] irq event stamp: 67260
> [ 12.260828] hardirqs last enabled at (67259): [<ffffff8008132d0c>] console_unlock+0x214/0x608
> [ 12.269693] hardirqs last disabled at (67260): [<ffffff8008080e0c>] do_debug_exception+0x5c/0x178
> [ 12.278820] softirqs last enabled at (67256): [<ffffff8008081664>] __do_softirq+0x4d4/0x520
> [ 12.287510] softirqs last disabled at (67249): [<ffffff80080be574>] irq_exit+0xa8/0x100
> [ 12.295742] ---[ end trace e63cfc40c313ffab ]---
>
> The root of the problem is that the default segment size for sgt is
> (UINT_MAX & PAGE_MASK), and the default segment size for device dma is
> 64K. As such, if you compare the 2, you would deduce that the sg segment
> will overflow the device's capacity. In reality, the hardware can
> accommodate the larger sg segments, it's just not initializing its max
> segment properly. This patch initializes the max segment size for the
> mdss device, which gets rid of that pesky warning.
>
> Reported-by: Stephen Boyd <swboyd@chromium.org>
> Signed-off-by: Sean Paul <seanpaul@chromium.org>
> Tested-by: Stephen Boyd <swboyd@chromium.org>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
> This patch has been floating in the ether for over a year [1]. I know
> next to nothing about it, but I'm told it's still useful so I'm
> helpfully reposting it. Please enjoy.
This looks like the right thing to do.. sorry I overlooked the patch
first time around
Reviewed-by: Rob Clark <robdclark@gmail.com>
(since I've already sent PR for msm-next, could we pick this up via drm-misc?)
BR,
-R
>
> [1] https://lore.kernel.org/r/20181106213239.52133-1-sean@poorly.run
>
> drivers/gpu/drm/msm/msm_drv.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index c26219c7a49f..e4b750b0c2d3 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -441,6 +441,14 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
> if (ret)
> goto err_msm_uninit;
>
> + if (!dev->dma_parms) {
> + dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
> + GFP_KERNEL);
> + if (!dev->dma_parms)
> + return -ENOMEM;
> + }
> + dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
> +
> msm_gem_shrinker_init(ddev);
>
> switch (get_mdp_ver(pdev)) {
> --
> 2.25.0.341.g760bfbb309-goog
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [REPOST PATCH] drm/msm: Set dma maximum segment size for mdss
2020-01-21 19:26 ` Rob Clark
@ 2020-01-22 14:14 ` Sai Prakash Ranjan
2020-01-22 14:51 ` Sean Paul
1 sibling, 0 replies; 5+ messages in thread
From: Sai Prakash Ranjan @ 2020-01-22 14:14 UTC (permalink / raw)
To: Rob Clark, Douglas Anderson
Cc: Matthias Kaehlcke, Stephen Boyd, Sean Paul, Sean Paul,
linux-arm-msm, Linux Kernel Mailing List, dri-devel,
David Airlie, freedreno, Daniel Vetter
Hi,
On 2020-01-22 00:56, Rob Clark wrote:
> On Tue, Jan 21, 2020 at 11:19 AM Douglas Anderson
> <dianders@chromium.org> wrote:
>>
>> From: Sean Paul <seanpaul@chromium.org>
>>
>> Turning on CONFIG_DMA_API_DEBUG_SG results in the following error:
>>
>> [ 12.078665] msm ae00000.mdss: DMA-API: mapping sg segment longer
>> than device claims to support [len=3526656] [max=65536]
>> [ 12.089870] WARNING: CPU: 6 PID: 334 at
>> /mnt/host/source/src/third_party/kernel/v4.19/kernel/dma/debug.c:1301
>> debug_dma_map_sg+0x1dc/0x318
>> [ 12.102655] Modules linked in: joydev
>> [ 12.106442] CPU: 6 PID: 334 Comm: frecon Not tainted 4.19.0 #2
>> [ 12.112450] Hardware name: Google Cheza (rev3+) (DT)
>> [ 12.117566] pstate: 60400009 (nZCv daif +PAN -UAO)
>> [ 12.122506] pc : debug_dma_map_sg+0x1dc/0x318
>> [ 12.126995] lr : debug_dma_map_sg+0x1dc/0x318
>> [ 12.131487] sp : ffffff800cc3ba80
>> [ 12.134913] x29: ffffff800cc3ba80 x28: 0000000000000000
>> [ 12.140395] x27: 0000000000000004 x26: 0000000000000004
>> [ 12.145868] x25: ffffff8008e55b18 x24: 0000000000000000
>> [ 12.151337] x23: 00000000ffffffff x22: ffffff800921c000
>> [ 12.156809] x21: ffffffc0fa75b080 x20: ffffffc0f7195090
>> [ 12.162280] x19: ffffffc0f1c53280 x18: 0000000000000000
>> [ 12.167749] x17: 0000000000000000 x16: 0000000000000000
>> [ 12.173218] x15: 0000000000000000 x14: 0720072007200720
>> [ 12.178689] x13: 0720072007200720 x12: 0720072007200720
>> [ 12.184161] x11: 0720072007200720 x10: 0720072007200720
>> [ 12.189641] x9 : ffffffc0f1fc6b60 x8 : 0000000000000000
>> [ 12.195110] x7 : ffffff8008132ce0 x6 : 0000000000000000
>> [ 12.200585] x5 : 0000000000000000 x4 : ffffff8008134734
>> [ 12.206058] x3 : ffffff800cc3b830 x2 : ffffffc0f1fc6240
>> [ 12.211532] x1 : 25045a74f48a7400 x0 : 25045a74f48a7400
>> [ 12.217006] Call trace:
>> [ 12.219535] debug_dma_map_sg+0x1dc/0x318
>> [ 12.223671] get_pages+0x19c/0x20c
>> [ 12.227177] msm_gem_fault+0x64/0xfc
>> [ 12.230874] __do_fault+0x3c/0x140
>> [ 12.234383] __handle_mm_fault+0x70c/0xdb8
>> [ 12.238603] handle_mm_fault+0xac/0xc4
>> [ 12.242473] do_page_fault+0x1bc/0x3d4
>> [ 12.246342] do_translation_fault+0x54/0x88
>> [ 12.250652] do_mem_abort+0x60/0xf0
>> [ 12.254250] el0_da+0x20/0x24
>> [ 12.257317] irq event stamp: 67260
>> [ 12.260828] hardirqs last enabled at (67259): [<ffffff8008132d0c>]
>> console_unlock+0x214/0x608
>> [ 12.269693] hardirqs last disabled at (67260): [<ffffff8008080e0c>]
>> do_debug_exception+0x5c/0x178
>> [ 12.278820] softirqs last enabled at (67256): [<ffffff8008081664>]
>> __do_softirq+0x4d4/0x520
>> [ 12.287510] softirqs last disabled at (67249): [<ffffff80080be574>]
>> irq_exit+0xa8/0x100
>> [ 12.295742] ---[ end trace e63cfc40c313ffab ]---
>>
>> The root of the problem is that the default segment size for sgt is
>> (UINT_MAX & PAGE_MASK), and the default segment size for device dma is
>> 64K. As such, if you compare the 2, you would deduce that the sg
>> segment
>> will overflow the device's capacity. In reality, the hardware can
>> accommodate the larger sg segments, it's just not initializing its max
>> segment properly. This patch initializes the max segment size for the
>> mdss device, which gets rid of that pesky warning.
>>
>> Reported-by: Stephen Boyd <swboyd@chromium.org>
>> Signed-off-by: Sean Paul <seanpaul@chromium.org>
>> Tested-by: Stephen Boyd <swboyd@chromium.org>
>> Signed-off-by: Douglas Anderson <dianders@chromium.org>
>> ---
>> This patch has been floating in the ether for over a year [1]. I know
>> next to nothing about it, but I'm told it's still useful so I'm
>> helpfully reposting it. Please enjoy.
>
> This looks like the right thing to do.. sorry I overlooked the patch
> first time around
>
> Reviewed-by: Rob Clark <robdclark@gmail.com>
>
> (since I've already sent PR for msm-next, could we pick this up via
> drm-misc?)
>
This also fixes a similar warning seen on SC7180 during video playback.
Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Logs for reference,
localhost ~ # [ 647.100504] ------------[ cut here ]------------
[ 647.105748] DMA-API: msm ae00000.mdss: mapping sg segment longer than
device claims to support [len=524288] [max=65536]
<...snip...>
[ 647.184254] pstate: 60400009 (nZCv daif +PAN -UAO)
[ 647.189211] pc : debug_dma_map_sg+0x1a8/0x2c4
[ 647.193708] lr : debug_dma_map_sg+0x1a8/0x2c4
[ 647.198202] sp : ffffffc010f6ba80
[ 647.201626] x29: ffffffc010f6ba90 x28: 0000000000010000
[ 647.207110] x27: 00000000ffffffff x26: ffffff8174840b80
[ 647.212592] x25: ffffffe9f4fe5000 x24: 0000000000000003
[ 647.218075] x23: ffffff815c223780 x22: ffffff81742d0810
[ 647.223557] x21: 0000000000000003 x20: 0000000000000001
[ 647.229041] x19: 0000000000000001 x18: 0000000000000000
[ 647.234524] x17: 000000000000003c x16: ffffffe9f4444a14
[ 647.240006] x15: 0000000000000006 x14: 0720072007200720
[ 647.245489] x13: 0720072007200720 x12: 0000000000000000
[ 647.250969] x11: 0000000000000000 x10: 0000000000000000
[ 647.256452] x9 : 4be0233cf8ef6200 x8 : 4be0233cf8ef6200
[ 647.261935] x7 : 0720072007200720 x6 : ffffff8175ea0f00
[ 647.267417] x5 : 0000000000000000 x4 : 0000000000000000
[ 647.272898] x3 : 0000000000000000 x2 : ffffff81771d1680
[ 647.278380] x1 : ffffff81771c10c0 x0 : 000000000000006b
[ 647.283863] Call trace:
[ 647.286409] debug_dma_map_sg+0x1a8/0x2c4
[ 647.290569] vb2_dma_sg_dmabuf_ops_map+0x138/0x18c [videobuf2_dma_sg]
[ 647.297215] dma_buf_map_attachment+0x6c/0xb0
[ 647.301724] drm_gem_prime_import_dev+0xa4/0x134
[ 647.306495] drm_gem_prime_fd_to_handle+0xc4/0x194
[ 647.311444] drm_prime_fd_to_handle_ioctl+0x40/0x58
[ 647.316483] drm_ioctl_kernel+0x94/0x10c
[ 647.320538] drm_ioctl+0x264/0x3f8
[ 647.324059] drm_compat_ioctl+0xcc/0xdc
[ 647.328033] __se_compat_sys_ioctl+0x100/0x2074
[ 647.332715] __arm64_compat_sys_ioctl+0x20/0x2c
[ 647.337406] el0_svc_common+0xa4/0x154
[ 647.341279] el0_svc_compat_handler+0x2c/0x38
[ 647.345781] el0_svc_compat+0x8/0x10
[ 647.349474] ---[ end trace 2f188eb70b295b6c ]---
[ 648.282197] ------------[ cut here ]------------
Thanks,
Sai
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a
member
of Code Aurora Forum, hosted by The Linux Foundation
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [REPOST PATCH] drm/msm: Set dma maximum segment size for mdss
2020-01-21 19:26 ` Rob Clark
2020-01-22 14:14 ` Sai Prakash Ranjan
@ 2020-01-22 14:51 ` Sean Paul
2020-01-22 15:43 ` Rob Clark
1 sibling, 1 reply; 5+ messages in thread
From: Sean Paul @ 2020-01-22 14:51 UTC (permalink / raw)
To: Rob Clark
Cc: Douglas Anderson, saiprakash.ranjan, Matthias Kaehlcke,
Stephen Boyd, Sean Paul, Sean Paul, linux-arm-msm,
Linux Kernel Mailing List, dri-devel, David Airlie, freedreno,
Daniel Vetter
On Tue, Jan 21, 2020 at 11:26:05AM -0800, Rob Clark wrote:
> On Tue, Jan 21, 2020 at 11:19 AM Douglas Anderson <dianders@chromium.org> wrote:
> >
> > From: Sean Paul <seanpaul@chromium.org>
> >
> > Turning on CONFIG_DMA_API_DEBUG_SG results in the following error:
> >
> > [ 12.078665] msm ae00000.mdss: DMA-API: mapping sg segment longer than device claims to support [len=3526656] [max=65536]
> > [ 12.089870] WARNING: CPU: 6 PID: 334 at /mnt/host/source/src/third_party/kernel/v4.19/kernel/dma/debug.c:1301 debug_dma_map_sg+0x1dc/0x318
> > [ 12.102655] Modules linked in: joydev
> > [ 12.106442] CPU: 6 PID: 334 Comm: frecon Not tainted 4.19.0 #2
> > [ 12.112450] Hardware name: Google Cheza (rev3+) (DT)
> > [ 12.117566] pstate: 60400009 (nZCv daif +PAN -UAO)
> > [ 12.122506] pc : debug_dma_map_sg+0x1dc/0x318
> > [ 12.126995] lr : debug_dma_map_sg+0x1dc/0x318
> > [ 12.131487] sp : ffffff800cc3ba80
> > [ 12.134913] x29: ffffff800cc3ba80 x28: 0000000000000000
> > [ 12.140395] x27: 0000000000000004 x26: 0000000000000004
> > [ 12.145868] x25: ffffff8008e55b18 x24: 0000000000000000
> > [ 12.151337] x23: 00000000ffffffff x22: ffffff800921c000
> > [ 12.156809] x21: ffffffc0fa75b080 x20: ffffffc0f7195090
> > [ 12.162280] x19: ffffffc0f1c53280 x18: 0000000000000000
> > [ 12.167749] x17: 0000000000000000 x16: 0000000000000000
> > [ 12.173218] x15: 0000000000000000 x14: 0720072007200720
> > [ 12.178689] x13: 0720072007200720 x12: 0720072007200720
> > [ 12.184161] x11: 0720072007200720 x10: 0720072007200720
> > [ 12.189641] x9 : ffffffc0f1fc6b60 x8 : 0000000000000000
> > [ 12.195110] x7 : ffffff8008132ce0 x6 : 0000000000000000
> > [ 12.200585] x5 : 0000000000000000 x4 : ffffff8008134734
> > [ 12.206058] x3 : ffffff800cc3b830 x2 : ffffffc0f1fc6240
> > [ 12.211532] x1 : 25045a74f48a7400 x0 : 25045a74f48a7400
> > [ 12.217006] Call trace:
> > [ 12.219535] debug_dma_map_sg+0x1dc/0x318
> > [ 12.223671] get_pages+0x19c/0x20c
> > [ 12.227177] msm_gem_fault+0x64/0xfc
> > [ 12.230874] __do_fault+0x3c/0x140
> > [ 12.234383] __handle_mm_fault+0x70c/0xdb8
> > [ 12.238603] handle_mm_fault+0xac/0xc4
> > [ 12.242473] do_page_fault+0x1bc/0x3d4
> > [ 12.246342] do_translation_fault+0x54/0x88
> > [ 12.250652] do_mem_abort+0x60/0xf0
> > [ 12.254250] el0_da+0x20/0x24
> > [ 12.257317] irq event stamp: 67260
> > [ 12.260828] hardirqs last enabled at (67259): [<ffffff8008132d0c>] console_unlock+0x214/0x608
> > [ 12.269693] hardirqs last disabled at (67260): [<ffffff8008080e0c>] do_debug_exception+0x5c/0x178
> > [ 12.278820] softirqs last enabled at (67256): [<ffffff8008081664>] __do_softirq+0x4d4/0x520
> > [ 12.287510] softirqs last disabled at (67249): [<ffffff80080be574>] irq_exit+0xa8/0x100
> > [ 12.295742] ---[ end trace e63cfc40c313ffab ]---
> >
> > The root of the problem is that the default segment size for sgt is
> > (UINT_MAX & PAGE_MASK), and the default segment size for device dma is
> > 64K. As such, if you compare the 2, you would deduce that the sg segment
> > will overflow the device's capacity. In reality, the hardware can
> > accommodate the larger sg segments, it's just not initializing its max
> > segment properly. This patch initializes the max segment size for the
> > mdss device, which gets rid of that pesky warning.
> >
> > Reported-by: Stephen Boyd <swboyd@chromium.org>
> > Signed-off-by: Sean Paul <seanpaul@chromium.org>
> > Tested-by: Stephen Boyd <swboyd@chromium.org>
> > Signed-off-by: Douglas Anderson <dianders@chromium.org>
> > ---
> > This patch has been floating in the ether for over a year [1]. I know
> > next to nothing about it, but I'm told it's still useful so I'm
> > helpfully reposting it. Please enjoy.
>
> This looks like the right thing to do.. sorry I overlooked the patch
> first time around
>
> Reviewed-by: Rob Clark <robdclark@gmail.com>
>
> (since I've already sent PR for msm-next, could we pick this up via drm-misc?)
You got it, pushed to drm-misc-next-fixes.
Thanks
Sean
>
> BR,
> -R
>
>
> >
> > [1] https://lore.kernel.org/r/20181106213239.52133-1-sean@poorly.run
> >
> > drivers/gpu/drm/msm/msm_drv.c | 8 ++++++++
> > 1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> > index c26219c7a49f..e4b750b0c2d3 100644
> > --- a/drivers/gpu/drm/msm/msm_drv.c
> > +++ b/drivers/gpu/drm/msm/msm_drv.c
> > @@ -441,6 +441,14 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
> > if (ret)
> > goto err_msm_uninit;
> >
> > + if (!dev->dma_parms) {
> > + dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
> > + GFP_KERNEL);
> > + if (!dev->dma_parms)
> > + return -ENOMEM;
> > + }
> > + dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
> > +
> > msm_gem_shrinker_init(ddev);
> >
> > switch (get_mdp_ver(pdev)) {
> > --
> > 2.25.0.341.g760bfbb309-goog
> >
--
Sean Paul, Software Engineer, Google / Chromium OS
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [REPOST PATCH] drm/msm: Set dma maximum segment size for mdss
2020-01-22 14:51 ` Sean Paul
@ 2020-01-22 15:43 ` Rob Clark
0 siblings, 0 replies; 5+ messages in thread
From: Rob Clark @ 2020-01-22 15:43 UTC (permalink / raw)
To: Sean Paul
Cc: Douglas Anderson, saiprakash.ranjan, Matthias Kaehlcke,
Stephen Boyd, Sean Paul, linux-arm-msm,
Linux Kernel Mailing List, dri-devel, David Airlie, freedreno,
Daniel Vetter
On Wed, Jan 22, 2020 at 6:51 AM Sean Paul <sean@poorly.run> wrote:
>
> On Tue, Jan 21, 2020 at 11:26:05AM -0800, Rob Clark wrote:
> > On Tue, Jan 21, 2020 at 11:19 AM Douglas Anderson <dianders@chromium.org> wrote:
> > >
> > > From: Sean Paul <seanpaul@chromium.org>
> > >
> > > Turning on CONFIG_DMA_API_DEBUG_SG results in the following error:
> > >
> > > [ 12.078665] msm ae00000.mdss: DMA-API: mapping sg segment longer than device claims to support [len=3526656] [max=65536]
> > > [ 12.089870] WARNING: CPU: 6 PID: 334 at /mnt/host/source/src/third_party/kernel/v4.19/kernel/dma/debug.c:1301 debug_dma_map_sg+0x1dc/0x318
> > > [ 12.102655] Modules linked in: joydev
> > > [ 12.106442] CPU: 6 PID: 334 Comm: frecon Not tainted 4.19.0 #2
> > > [ 12.112450] Hardware name: Google Cheza (rev3+) (DT)
> > > [ 12.117566] pstate: 60400009 (nZCv daif +PAN -UAO)
> > > [ 12.122506] pc : debug_dma_map_sg+0x1dc/0x318
> > > [ 12.126995] lr : debug_dma_map_sg+0x1dc/0x318
> > > [ 12.131487] sp : ffffff800cc3ba80
> > > [ 12.134913] x29: ffffff800cc3ba80 x28: 0000000000000000
> > > [ 12.140395] x27: 0000000000000004 x26: 0000000000000004
> > > [ 12.145868] x25: ffffff8008e55b18 x24: 0000000000000000
> > > [ 12.151337] x23: 00000000ffffffff x22: ffffff800921c000
> > > [ 12.156809] x21: ffffffc0fa75b080 x20: ffffffc0f7195090
> > > [ 12.162280] x19: ffffffc0f1c53280 x18: 0000000000000000
> > > [ 12.167749] x17: 0000000000000000 x16: 0000000000000000
> > > [ 12.173218] x15: 0000000000000000 x14: 0720072007200720
> > > [ 12.178689] x13: 0720072007200720 x12: 0720072007200720
> > > [ 12.184161] x11: 0720072007200720 x10: 0720072007200720
> > > [ 12.189641] x9 : ffffffc0f1fc6b60 x8 : 0000000000000000
> > > [ 12.195110] x7 : ffffff8008132ce0 x6 : 0000000000000000
> > > [ 12.200585] x5 : 0000000000000000 x4 : ffffff8008134734
> > > [ 12.206058] x3 : ffffff800cc3b830 x2 : ffffffc0f1fc6240
> > > [ 12.211532] x1 : 25045a74f48a7400 x0 : 25045a74f48a7400
> > > [ 12.217006] Call trace:
> > > [ 12.219535] debug_dma_map_sg+0x1dc/0x318
> > > [ 12.223671] get_pages+0x19c/0x20c
> > > [ 12.227177] msm_gem_fault+0x64/0xfc
> > > [ 12.230874] __do_fault+0x3c/0x140
> > > [ 12.234383] __handle_mm_fault+0x70c/0xdb8
> > > [ 12.238603] handle_mm_fault+0xac/0xc4
> > > [ 12.242473] do_page_fault+0x1bc/0x3d4
> > > [ 12.246342] do_translation_fault+0x54/0x88
> > > [ 12.250652] do_mem_abort+0x60/0xf0
> > > [ 12.254250] el0_da+0x20/0x24
> > > [ 12.257317] irq event stamp: 67260
> > > [ 12.260828] hardirqs last enabled at (67259): [<ffffff8008132d0c>] console_unlock+0x214/0x608
> > > [ 12.269693] hardirqs last disabled at (67260): [<ffffff8008080e0c>] do_debug_exception+0x5c/0x178
> > > [ 12.278820] softirqs last enabled at (67256): [<ffffff8008081664>] __do_softirq+0x4d4/0x520
> > > [ 12.287510] softirqs last disabled at (67249): [<ffffff80080be574>] irq_exit+0xa8/0x100
> > > [ 12.295742] ---[ end trace e63cfc40c313ffab ]---
> > >
> > > The root of the problem is that the default segment size for sgt is
> > > (UINT_MAX & PAGE_MASK), and the default segment size for device dma is
> > > 64K. As such, if you compare the 2, you would deduce that the sg segment
> > > will overflow the device's capacity. In reality, the hardware can
> > > accommodate the larger sg segments, it's just not initializing its max
> > > segment properly. This patch initializes the max segment size for the
> > > mdss device, which gets rid of that pesky warning.
> > >
> > > Reported-by: Stephen Boyd <swboyd@chromium.org>
> > > Signed-off-by: Sean Paul <seanpaul@chromium.org>
> > > Tested-by: Stephen Boyd <swboyd@chromium.org>
> > > Signed-off-by: Douglas Anderson <dianders@chromium.org>
> > > ---
> > > This patch has been floating in the ether for over a year [1]. I know
> > > next to nothing about it, but I'm told it's still useful so I'm
> > > helpfully reposting it. Please enjoy.
> >
> > This looks like the right thing to do.. sorry I overlooked the patch
> > first time around
> >
> > Reviewed-by: Rob Clark <robdclark@gmail.com>
> >
> > (since I've already sent PR for msm-next, could we pick this up via drm-misc?)
>
> You got it, pushed to drm-misc-next-fixes.
>
thx
BR,
-R
> Thanks
>
> Sean
>
> >
> > BR,
> > -R
> >
> >
> > >
> > > [1] https://lore.kernel.org/r/20181106213239.52133-1-sean@poorly.run
> > >
> > > drivers/gpu/drm/msm/msm_drv.c | 8 ++++++++
> > > 1 file changed, 8 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> > > index c26219c7a49f..e4b750b0c2d3 100644
> > > --- a/drivers/gpu/drm/msm/msm_drv.c
> > > +++ b/drivers/gpu/drm/msm/msm_drv.c
> > > @@ -441,6 +441,14 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
> > > if (ret)
> > > goto err_msm_uninit;
> > >
> > > + if (!dev->dma_parms) {
> > > + dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
> > > + GFP_KERNEL);
> > > + if (!dev->dma_parms)
> > > + return -ENOMEM;
> > > + }
> > > + dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
> > > +
> > > msm_gem_shrinker_init(ddev);
> > >
> > > switch (get_mdp_ver(pdev)) {
> > > --
> > > 2.25.0.341.g760bfbb309-goog
> > >
>
> --
> Sean Paul, Software Engineer, Google / Chromium OS
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-01-22 15:43 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-01-21 19:18 [REPOST PATCH] drm/msm: Set dma maximum segment size for mdss Douglas Anderson
2020-01-21 19:26 ` Rob Clark
2020-01-22 14:14 ` Sai Prakash Ranjan
2020-01-22 14:51 ` Sean Paul
2020-01-22 15:43 ` Rob Clark
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