From dd05add7b2b6004c5fa3a1f276f56d8668f86b65 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sat, 26 Sep 2026 19:20:30 -0300 Subject: netfs: zero the tail of a short DIO/unbuffered read The buffered read collector zero-fills the tail of a short read that stops below the inode's i_size (netfs_clear_unread()), so a read that races an extending write still returns the expected number of bytes. The non-buffered collector path does no such thing: it just records how much was transferred. Add the same zero-fill for the non-buffered case, gated on NETFS_SREQ_CLEAR_TAIL: a subreq's source sets that flag when a short result from it is known to be safe to treat as a hole, as opposed to NETFS_SREQ_HIT_EOF, which means the read genuinely ran off the end of the file and should be reported short as-is. Only CLEAR_TAIL should zero-fill here; a real EOF must stay a real short read. No source currently sets CLEAR_TAIL on an unbuffered/DIO subrequest, so this is inert on its own -- a following change teaches cifs to set it in the one case that needs it. Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Reviewed-by: David Howells Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Cc: Christian Brauner Cc: Matthew Wilcox Cc: Ronnie Sahlberg Cc: Shyam Prasad N Cc: Tom Talpey Cc: Bharath SM Cc: stable@vger.kernel.org --- Documentation/gpu/amdgpu/flashing.rst | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 Documentation/gpu/amdgpu/flashing.rst (limited to 'Documentation/gpu/amdgpu/flashing.rst') diff --git a/Documentation/gpu/amdgpu/flashing.rst b/Documentation/gpu/amdgpu/flashing.rst new file mode 100644 index 000000000..bd745c42a --- /dev/null +++ b/Documentation/gpu/amdgpu/flashing.rst @@ -0,0 +1,33 @@ +======================= + dGPU firmware flashing +======================= + +IFWI +---- +Flashing the dGPU integrated firmware image (IFWI) is supported by GPUs that +use the PSP to orchestrate the update (Navi3x or newer GPUs). +For supported GPUs, `amdgpu` will export a series of sysfs files that can be +used for the flash process. + +The IFWI flash process is: + +1. Ensure the IFWI image is intended for the dGPU on the system. +2. "Write" the IFWI image to the sysfs file `psp_vbflash`. This will stage the IFWI in memory. +3. "Read" from the `psp_vbflash` sysfs file to initiate the flash process. +4. Poll the `psp_vbflash_status` sysfs file to determine when the flash process completes. + +USB-C PD F/W +------------ +On GPUs that support flashing an updated USB-C PD firmware image, the process +is done using the `usbc_pd_fw` sysfs file. + +* Reading the file will provide the current firmware version. +* Writing the name of a firmware payload stored in `/lib/firmware/amdgpu` to the sysfs file will initiate the flash process. + +The firmware payload stored in `/lib/firmware/amdgpu` can be named any name +as long as it doesn't conflict with other existing binaries that are used by +`amdgpu`. + +sysfs files +----------- +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c -- cgit v1.3.1