From 59b7ed0ba2e0fc18dda19a2c48eea2c3cef652f3 Mon Sep 17 00:00:00 2001 From: Lucas De Marchi Date: Wed, 24 Sep 2025 08:27:11 -0700 Subject: [PATCH] drm/xe/configfs: Improve doc for ctx_restore* attributes Spell out the syntax instead of only using examples. Particularly important the part since that's different than engines_allowed and may confuse users. The same batch buffer is used for all engines of a certain class. Cc: Raag Jadav Reviewed-by: Raag Jadav Reviewed-by: Jonathan Cavitt Fixes: e2a9854d806e ("drm/xe/configfs: Allow to select by class only") Link: https://lore.kernel.org/r/20250924152709.659483-4-lucas.demarchi@intel.com Signed-off-by: Lucas De Marchi (cherry picked from commit 47ca7acff4011fa322853a3612f464b959e88210) Signed-off-by: Lucas De Marchi --- drivers/gpu/drm/xe/xe_configfs.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/xe/xe_configfs.c b/drivers/gpu/drm/xe/xe_configfs.c index beade13efbae..139663423185 100644 --- a/drivers/gpu/drm/xe/xe_configfs.c +++ b/drivers/gpu/drm/xe/xe_configfs.c @@ -126,8 +126,20 @@ * not intended for normal execution and will taint the kernel with TAINT_TEST * when used. * - * Currently this is implemented only for post and mid context restore. - * Examples: + * The syntax allows to pass straight instructions to be executed by the engine + * in a batch buffer or set specific registers. + * + * #. Generic instruction:: + * + * cmd [[dword0] [dword1] [...]] + * + * #. Simple register setting:: + * + * reg
+ * + * Commands are saved per engine class: all instances of that class will execute + * those commands during context switch. The instruction, dword arguments, + * addresses and values are in hex format like in the examples below. * * #. Execute a LRI command to write 0xDEADBEEF to register 0x4f10 after the * normal context restore:: @@ -154,7 +166,8 @@ * When using multiple lines, make sure to use a command that is * implemented with a single write syscall, like HEREDOC. * - * These attributes can only be set before binding to the device. + * Currently this is implemented only for post and mid context restore and + * these attributes can only be set before binding to the device. * * Remove devices * ============== -- 2.51.0