[PATCH V5 17/17] i3c: mipi-i3c-hci: Increase DMA transfer ring size to maximum
Adrian Hunter <[email protected]>
| Newsgroups | org.infradead.lists.linux-i3c,org.kernel.vger.linux-kernel |
|---|---|
| Organization | Intel Finland Oy, Registered Address: c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo, Business Identity Code: 0357606 - 4, Domiciled in Helsinki |
| Message-ID | <[email protected]> |
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 <[email protected]> Reviewed-by: Frank Li <[email protected]> --- Changes in V5: None Changes in V4: Add Frank's Rev'd-by Changes in V2 and V3: None drivers/i3c/master/mipi-i3c-hci/dma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c index 0136f3064ada..5c6ae2055618 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 */ -- 2.51.0 -- linux-i3c mailing list [email protected] http://lists.infradead.org/mailman/listinfo/linux-i3c