From: Adrian Hunter Date: Wed, 3 Jun 2026 09:07:54 +0000 (+0300) Subject: i3c: mipi-i3c-hci: Increase DMA transfer ring size to maximum X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e62fe9f267716a1ea0313a6ab8fb28d1cfb8aaf5;p=thirdparty%2Flinux.git i3c: mipi-i3c-hci: Increase DMA transfer ring size to maximum The DMA transfer ring is currently limited to 16 entries, despite the MIPI I3C HCI supporting up to 32 devices. When the ring lacks space for a new transfer list, the driver returns -EBUSY, which can be unexpected for clients. Increase the DMA transfer ring size to the maximum supported value of 255 entries. This effectively eliminates ring-space exhaustion in practice and avoids the complexity of adding secondary queuing mechanisms. Even at the maximum size, the memory overhead remains small (approximately 24 bytes per entry by default). Signed-off-by: Adrian Hunter Reviewed-by: Frank Li Link: https://patch.msgid.link/20260603090754.16252-18-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni --- diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c index 0136f3064adab..5c6ae20556184 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -27,7 +27,7 @@ */ #define XFER_RINGS 1 /* max: 8 */ -#define XFER_RING_ENTRIES 16 /* max: 255 */ +#define XFER_RING_ENTRIES 255 /* max: 255 */ #define IBI_RINGS 1 /* max: 8 */ #define IBI_STATUS_RING_ENTRIES 32 /* max: 255 */