[reactos] 02/04: [SERIAL] Immediately complete read IRP if all requested bytes have been found in circular buffer

[Hervé Poussineau]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=bef39dd62ee62a2b7c0eb…

commit bef39dd62ee62a2b7c0eb1a3749dee0c700b5188
Author:     Hervé Poussineau <hpoussin(a)reactos.org>
AuthorDate: Thu May 2 13:26:46 2019 +0200
Commit:     Hervé Poussineau <hpoussin(a)reactos.org>
CommitDate: Thu May 2 20:06:47 2019 +0200

    [SERIAL] Immediately complete read IRP if all requested bytes have been found in
circular buffer
    
    Previously, we had to wait to receive another byte to finish the first IRP.
---
 drivers/serial/serial/rw.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/serial/serial/rw.c b/drivers/serial/serial/rw.c
index df101ca07b..4179ac820b 100644
--- a/drivers/serial/serial/rw.c
+++ b/drivers/serial/serial/rw.c
@@ -65,7 +65,7 @@ ReadBytes(
 	}
 
 	/* while buffer is not fully filled */
-	while (Length > 0)
+	while (TRUE)
 	{
 		/* read already received bytes from buffer */
 		KeAcquireSpinLock(&DeviceExtension->InputBufferLock, &Irql);
@@ -81,6 +81,12 @@ ReadBytes(
 		KeClearEvent(&DeviceExtension->InputBufferNotEmpty);
 		KeReleaseSpinLock(&DeviceExtension->InputBufferLock, Irql);
 
+		if (Length == 0)
+		{
+			INFO_(SERIAL, "All bytes read\n");
+			break;
+		}
+
 		if (WorkItemData->DontWait
 			&& !(WorkItemData->ReadAtLeastOneByte && Information == 0))
 		{