1. Patchew
  2. linux
  3. View series

[PATCH] drm/imagination: Align rogue_fwif_hwrtdata to 64 bytes

Michal Wilczynski posted 1 patch 1 month, 2 weeks ago 
drivers/gpu/drm/imagination/pvr_rogue_fwif.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
[PATCH] drm/imagination: Align rogue_fwif_hwrtdata to 64 bytes
Posted by Michal Wilczynski 1 month, 2 weeks ago 
The build fails on RISC-V using GCC because `SIZE_CHECK(struct
rogue_fwif_hwrtdata, 384)` expects 384 bytes, but the compiler generates
a 336-byte structure.

This is due to an alignment conflict: the inner member `cleanup_state`
requires 64-byte alignment, but the outer struct is explicitly marked
`__aligned(8)`.

While GCC on ARM64 implicitly pads the size to a multiple of 64, GCC on
RISC-V strictly respects the 8-byte outer alignment, resulting in a size
mismatch.

Fix this by aligning the entire structure to 64 bytes, which resolves
the contradiction and forces the correct 384 byte size on all
architectures.

Fixes: a26f067feac1 ("drm/imagination: Add FWIF headers")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202512131851.1WNXk3BC-lkp@intel.com/
Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>
---
 drivers/gpu/drm/imagination/pvr_rogue_fwif.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/imagination/pvr_rogue_fwif.h b/drivers/gpu/drm/imagination/pvr_rogue_fwif.h
index 172886be4c820a32ae1b08d62bf0814250f2a9bd..1ba2a167a38b31911e0846923e4dc70626f5ca65 100644
--- a/drivers/gpu/drm/imagination/pvr_rogue_fwif.h
+++ b/drivers/gpu/drm/imagination/pvr_rogue_fwif.h
@@ -2170,7 +2170,7 @@ struct rogue_fwif_hwrtdata {
 	bool geom_caches_need_zeroing __aligned(4);
 
 	struct rogue_fwif_cleanup_ctl cleanup_state __aligned(64);
-} __aligned(8);
+} __aligned(64);
 
 /*
  ******************************************************************************

---
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
change-id: 20251222-fix_imagination-8ef0c94122c4

Best regards,
-- 
Michal Wilczynski <m.wilczynski@samsung.com>
Re: [PATCH] drm/imagination: Align rogue_fwif_hwrtdata to 64 bytes
Posted by Matt Coster 1 month ago 
On 22/12/2025 22:53, Michal Wilczynski wrote:
> The build fails on RISC-V using GCC because `SIZE_CHECK(struct
> rogue_fwif_hwrtdata, 384)` expects 384 bytes, but the compiler generates
> a 336-byte structure.
> 
> This is due to an alignment conflict: the inner member `cleanup_state`
> requires 64-byte alignment, but the outer struct is explicitly marked
> `__aligned(8)`.
> 
> While GCC on ARM64 implicitly pads the size to a multiple of 64, GCC on
> RISC-V strictly respects the 8-byte outer alignment, resulting in a size
> mismatch.
> 
> Fix this by aligning the entire structure to 64 bytes, which resolves
> the contradiction and forces the correct 384 byte size on all
> architectures.
> 
> Fixes: a26f067feac1 ("drm/imagination: Add FWIF headers")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202512131851.1WNXk3BC-lkp@intel.com/ 
> Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>

Hi Michal,

This looks fine to me. I'm surprised the behaviour of GCC differs by
architecture though, is there a bug somewhere or is it UB to explicitly
narrow the alignment like this? Either way:

Reviewed-by: Matt Coster <matt.coster@imgtec.com>

And I'll take via drm-misc-fixes tomorrow.

Cheers,
Matt

> ---
>  drivers/gpu/drm/imagination/pvr_rogue_fwif.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/imagination/pvr_rogue_fwif.h b/drivers/gpu/drm/imagination/pvr_rogue_fwif.h
> index 172886be4c820a32ae1b08d62bf0814250f2a9bd..1ba2a167a38b31911e0846923e4dc70626f5ca65 100644
> --- a/drivers/gpu/drm/imagination/pvr_rogue_fwif.h
> +++ b/drivers/gpu/drm/imagination/pvr_rogue_fwif.h
> @@ -2170,7 +2170,7 @@ struct rogue_fwif_hwrtdata {
>  	bool geom_caches_need_zeroing __aligned(4);
>  
>  	struct rogue_fwif_cleanup_ctl cleanup_state __aligned(64);
> -} __aligned(8);
> +} __aligned(64);
>  
>  /*
>   ******************************************************************************
> 
> ---
> base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
> change-id: 20251222-fix_imagination-8ef0c94122c4
> 
> Best regards,

-- 
Matt Coster
E: matt.coster@imgtec.com
Re: [PATCH] drm/imagination: Align rogue_fwif_hwrtdata to 64 bytes
Posted by kernel test robot 1 month, 2 weeks ago 
Hi Michal,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 8f0b4cce4481fb22653697cced8d0d04027cb1e8]

url:    https://github.com/intel-lab-lkp/linux/commits/Michal-Wilczynski/drm-imagination-Align-rogue_fwif_hwrtdata-to-64-bytes/20251223-065827
base:   8f0b4cce4481fb22653697cced8d0d04027cb1e8
patch link:    https://lore.kernel.org/r/20251222-fix_imagination-v1-1-0ac80a2ff317%40samsung.com
patch subject: [PATCH] drm/imagination: Align rogue_fwif_hwrtdata to 64 bytes
config: arm64-randconfig-r113-20251224 (https://download.01.org/0day-ci/archive/20251224/202512241051.keF0EcdF-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 11.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251224/202512241051.keF0EcdF-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202512241051.keF0EcdF-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/gpu/drm/imagination/pvr_power.c:62:16: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void const volatile [noderef] __iomem *addr @@     got unsigned int [usertype] *power_sync @@
   drivers/gpu/drm/imagination/pvr_power.c:62:16: sparse:     expected void const volatile [noderef] __iomem *addr
   drivers/gpu/drm/imagination/pvr_power.c:62:16: sparse:     got unsigned int [usertype] *power_sync

vim +62 drivers/gpu/drm/imagination/pvr_power.c

cc1aeedb98ad34 Sarah Walker 2023-11-22  46  
727538a4bbff07 Sarah Walker 2023-11-22  47  static int
727538a4bbff07 Sarah Walker 2023-11-22  48  pvr_power_send_command(struct pvr_device *pvr_dev, struct rogue_fwif_kccb_cmd *pow_cmd)
727538a4bbff07 Sarah Walker 2023-11-22  49  {
cc1aeedb98ad34 Sarah Walker 2023-11-22  50  	struct pvr_fw_device *fw_dev = &pvr_dev->fw_dev;
cc1aeedb98ad34 Sarah Walker 2023-11-22  51  	u32 slot_nr;
cc1aeedb98ad34 Sarah Walker 2023-11-22  52  	u32 value;
cc1aeedb98ad34 Sarah Walker 2023-11-22  53  	int err;
cc1aeedb98ad34 Sarah Walker 2023-11-22  54  
cc1aeedb98ad34 Sarah Walker 2023-11-22  55  	WRITE_ONCE(*fw_dev->power_sync, 0);
cc1aeedb98ad34 Sarah Walker 2023-11-22  56  
cc1aeedb98ad34 Sarah Walker 2023-11-22  57  	err = pvr_kccb_send_cmd_powered(pvr_dev, pow_cmd, &slot_nr);
cc1aeedb98ad34 Sarah Walker 2023-11-22  58  	if (err)
cc1aeedb98ad34 Sarah Walker 2023-11-22  59  		return err;
cc1aeedb98ad34 Sarah Walker 2023-11-22  60  
cc1aeedb98ad34 Sarah Walker 2023-11-22  61  	/* Wait for FW to acknowledge. */
cc1aeedb98ad34 Sarah Walker 2023-11-22 @62  	return readl_poll_timeout(pvr_dev->fw_dev.power_sync, value, value != 0, 100,
cc1aeedb98ad34 Sarah Walker 2023-11-22  63  				  POWER_SYNC_TIMEOUT_US);
727538a4bbff07 Sarah Walker 2023-11-22  64  }
727538a4bbff07 Sarah Walker 2023-11-22  65  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Patchew 2.1-devel-b67e4c2

© 2016 - 2026 Red Hat, Inc.